Mask system

ABSTRACT

A mask system for use between a patient and a device to deliver a breathable gas to the patient includes a mouth cushion, a pair of nasal prongs, an elbow, and a headgear assembly. The mouth cushion is structured to sealingly engage around an exterior of a patient&#39;s mouth in use, and the pair of nasal prongs are structured to sealingly communicate with nasal passages of a patient&#39;s nose in use. The elbow delivers breathable gas to the patient. The headgear assembly maintains the mouth cushion and the nasal prongs in a desired position on the patient&#39;s face. The headgear assembly provides a substantially round crown strap that cups the parietal bone and occipital bone of the patient&#39;s head in use.

CROSS-REFERENCE TO APPLICATIONS

This application claims the benefit of U.S. Provisional Application Nos.60/687,453, filed Jun. 6, 2005, 60/702,581, filed Jul. 27, 2005, and60/795,562, filed Apr. 28, 2006, each of which is incorporated herein byreference in its entirety.

Also, PCT Application No. PCT/AU2004/001832, filed Dec. 24, 2004, isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a mask system for delivery ofrespiratory therapy to a patient. Examples of such therapies areContinuous Positive Airway Pressure (CPAP) treatment, Non-InvasivePositive Pressure Ventilation (NIPPV), and Variable Positive AirwayPressure (VPAP). The therapy is used for treatment of variousrespiratory conditions including Sleep Disordered Breathing (SDB) suchas Obstructive Sleep Apnea (OSA).

BACKGROUND OF THE INVENTION

Mask systems form an interface between a patient and apparatus providinga supply of pressurized air or breathing gas and are hence sometimesreferred to as patient interfaces. In this specification, the words masksystem and patient interface will be used interchangably. Mask systemsin the field of the invention differ from mask systems used in otherapplications such as aviation and safety in particular because of theiremphasis on comfort. This high level of comfort is desired becausepatients must sleep wearing the masks for hours, possibly each night forthe rest of their lives. Mask systems typically, although not always,comprise (i) a rigid or semi-rigid portion often referred to as a shellor frame, (ii) a soft, patient contacting portion often referred to as acushion, and (iii) some form of headgear to hold the frame and cushionin position. Mask systems often include a mechanism for connecting anair delivery conduit. The air delivery conduit is usually connected to ablower or flow generator.

A range of patient interfaces are known including nasal masks, nose &mouth masks, full face masks and nasal prongs, pillows, nozzles &cannulae. Masks typically cover more of the face than nasal prongs,pillows, nozzles and cannulae. In this specification, all will becollectively referred to as patient interfaces or mask systems. Nasalprongs, nasal pillows, nozzles and cannulae all will be collectivelyreferred to as nasal prongs.

An inherent characteristic of nasal masks is that they do not seal themouth region. A number of patients thus find that during sleep whenmuscles relax, mouth leak may occur. Alternatively, some patients arenaturally mouth breathers and thus find a nasal mask type patientinterface ineffective. Mouth leak is undesirable as, among otherdifficulties, it may result in noise, increased treatment pressure tocompensate for the leak or an increased load on the nasal passages andpotentially nasal obstruction or a runny nose. Full face masks or nose &mouth masks address this issue by sealing around both the nose and themouth.

Leak is a problem common to all designs of patient interface. Sincenasal bridge anthropometry varies greatly between patients, the softpatient contacting portion or cushion must adapt to the shapes ofindividual patients. Typically, this is not achieved for the entirerange of patients and some form of leak occurs. The problem isheightened during sleep when the jaw moves and the head positionchanges. This action can often serve to dislodge the mask and causeleak. Since leak can be noisy and results in less-effective treatment,users often compensate by tightening the headgear more than is desired.This is detrimental for patient comfort and can cause skin breakdown orirritation.

A further problem encountered by patients who are using full face, nasalor nose and mouth masks is that the portion of the patient interfacethat seals around the nasal bridge prevents the patient from wearingspectacles. Additionally, it may give the sensation of being closed in,leading to a feeling of claustrophobia, particularly when combined witha mouth-sealing portion. A further disadvantage is that any leaks thatmay occur can affect the sensitive area surrounding the eyes.

Thus, there is a need for an improved mask system that does not sufferfrom the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

A mask system in accordance with a first aspect of the inventionprovides unobtrusive, comfortable, quiet, effective therapy to apatient's mouth and nasal passages. In one form, this is achieved byproviding a mouth cushion with nasal prongs having a mask frame held ina stable position by a headgear including stabilizing elements. Theheadgear according to an embodiment of the present invention uniquelyprovide unobtrusive sealing for both the nose and mouth. The nasalprongs and mouth cushion according to an embodiment of the presentinvention can accommodate and seal with a wide range of different facialshapes. A vent according to an embodiment of the present inventionprovides quiet washout of exhaled gases. A swiveling elbow according toan embodiment of the present invention incorporates an anti-asphyxiavalve that is effective and simple to use.

A form of headgear in accordance with an embodiment of the inventionprovides a sealing or retaining force against the mouth and against thenares. In one form the headgear includes a stabilizing element that hasa generally serpentine shape that allows a retaining force be directedagainst the nares and allows the headgear to circumvent the eyes.

A form of nasal prong in accordance with an embodiment of the inventionhas an articulated base region and an articulated head region. In oneform a prong includes a base region having two joints and a head regionhaving two joints.

A nasal prong in accordance with an embodiment of the invention includesa seal-forming portion and a structure-defining portion. In one form theprong has dual walls comprising a thin seal-forming wall and a thickerstructure-defining wall.

Another aspect of the present invention relates to a mask system for usebetween a patient and a device to deliver a breathable gas to thepatient. The mask system includes a mouth cushion, a pair of nasalprongs, an elbow, and a headgear assembly. The mouth cushion isstructured to sealingly engage around an exterior of a patient's mouthin use, and the pair of nasal prongs are structured to sealinglycommunicate with nasal passages of a patient's nose in use. The elbowdelivers breathable gas to the patient. The headgear assembly maintainsthe mouth cushion and the nasal prongs in a desired position on thepatient's face. The headgear assembly provides a substantially roundcrown strap that cups the parietal bone and occipital bone of thepatient's head in use. In an embodiment, the headgear assembly isconstructed from two-dimensional first and second headgear sections thatare attached to one another to form a three-dimensionalanatomically-shaped headgear assembly.

Another aspect of the present invention relates to a mask system for usebetween a patient and a device to deliver a breathable gas to thepatient. The mask system includes a mouth cushion, a pair of nasalprongs, an inlet conduit, and a headgear assembly. The mouth cushion isstructured to sealingly engage around an exterior of a patient's mouthin use, and the pair of nasal prongs are structured to sealinglycommunicate with nasal passages of a patient's nose in use. The inletconduit is structured to deliver breathable gas to the patient. Theheadgear assembly maintains the mouth cushion and the nasal prongs in adesired position on the patient's face. The headgear assembly includes aretainer that retains the inlet conduit so that the inlet conduitextends up and around the patient's ears in use.

Another aspect of the invention relates to a headgear assembly for amask system including a two-dimensional first headgear section and atwo-dimensional second headgear section. The two-dimensional first andsecond headgear sections are attached to one another to form athree-dimensional anatomically-shaped headgear assembly.

Yet another aspect of the invention relates to a method for forming aheadgear assembly for a mask system. The method includes forming atwo-dimensional first headgear section, forming a two-dimensional secondheadgear section, and attaching the two-dimensional first and secondheadgear sections to one another to form a three-dimensionalanatomically-shaped headgear assembly.

Still another aspect of the invention relates to a nasal prong forsealing with a nasal passage of a patient. The nasal prong includes ahead portion structured to seal with the patient's nasal passage and abase portion structured to mount the nasal prong to a support structure.The base portion includes a horizontal segment, a radial segment, and avertical segment that provide the base portion with a trampoline-likestructure to add flexibility at the base portion.

A further aspect of the invention relates to a mask system including aplurality of headgear straps, a sealing assembly, and a stabilizingstructure extending between the sealing assembly and at least a selectedone of the headgear straps. The stabilizing structure is substantiallyrigid and has a preformed three-dimensional shape substantially matchingthe shape of a portion of the patient's face.

Still another aspect of the invention relates to a sealing assembly fora mask system. The sealing assembly includes a mouth cushion adapted tosealingly engage around an exterior of a patient's mouth in use, and anasal prong insert provided to the mouth cushion. The nasal prong insertincludes a pair of nasal prongs adapted to sealingly communicate withrespective nasal passages of a patient in use and a bridging strap tointerconnect the pair of nasal prongs.

Still another aspect of the invention relates to a nasal prong insertincluding a pair of nasal prongs adapted to sealingly communicate withrespective nasal passages of a patient in use and a bridging strap tointerconnect the pair of nasal prongs. Still another aspect of theinvention relates to a mask system for delivering breathable gas to apatient. The mask system includes a frame, a mouth cushion provided tothe frame, and a pair of nasal prongs provided to the mouth cushion. Themouth cushion is adapted to sealingly engage around an exterior of apatient's mouth in use. The pair of nasal prongs is adapted to sealinglycommunicate with respective nasal passages of a patient in use. An elbowis provided to deliver breathable gas to the patient. A headgearassembly is removably connected to the frame so as to maintain the mouthcushion and the pair of nasal prongs in a desired position on thepatient's face. The headgear assembly includes upper headgear straps,lower headgear straps, upper stabilizing elements extending between theupper headgear straps and the frame, and lower stabilizing elementsextending between the lower headgear straps and the frame. The upper andlower stabilizing elements are bendable along at least one bending planeso as to conform to the shape of a portion of the patient's face.

Yet another aspect of the invention relates to a method for defining acushion shape. The method includes selecting at least three points onthe cushion, defining coordinates for each of the at least three points,and smoothly transitioning the shape of the cushion between the at leastthree points along the cushion perimeter.

Yet another aspect of the invention relates to a mask system including aplurality of headgear straps including at least upper straps, a sealingassembly, and an upper stabilizing element extending between the sealingassembly and the upper straps. The upper stabilizing element includes anelongated element having an intermediate portion attachable to thesealing assembly and end portions attachable to respective upper straps.

Yet another aspect of the invention relates to an integrally moldednasal prong including a first substantially frusto-conical portion, asecond substantially frusto-conical portion, and a connecting portionthat interconnects the first and second conical portions. The connectingportion is configured to allow the first frusto-conical portion to foldinto a position adjacent the second frusto-conical portion to provide adual wall construction.

Yet another aspect of the invention relates to an elbow assembly for amask system. The elbow assembly includes an elbow including a slot and aport, an anti-asphyxia valve adapted to be received within the slot andincluding a flap portion adapted to selectively close the port dependingon the presence of pressurized gas, and a clip member to secure theanti-asphyxia valve to the elbow. The clip member includes a slot thatis adapted to interlock with a protrusion provided to the anti-asphyxiavalve. The clip member has a vertically extending rib that is locatedagainst an outer surface of the elbow when secured to the elbow. The ribis adapted to prevent assembly of the flap portion between the rib andthe outer surface.

Another aspect of the invention relates to a mask system including asealing assembly having prongs, a trampoline base provided to theprongs, headgear, and stabilizing elements between the headgear andsealing assembly. The trampoline base allows the prongs to move axially.In an embodiment, the prongs each have dual wall construction.

Another aspect of the invention relates to an elbow assembly for a masksystem. The elbow assembly includes an elbow including a slot and aport, an anti-asphyxia valve adapted to be received within the slot andincluding a flap portion adapted to selectively close the port dependingon the presence of pressurized gas, and a clip member to secure theanti-asphyxia valve to the elbow. The clip member includes a slot thatis adapted to interlock with a protrusion provided to the anti-asphyxiavalve. The clip member has a vertically extending rib that is locatedagainst an outer surface of the elbow when secured to the elbow. The ribis adapted to prevent assembly of the flap portion between the rib andthe outer surface.

Another aspect of the invention relates to a mask system for deliveringbreathable gas to a patient. The mask system includes a frame, a mouthcushion provided to the frame, a pair of nasal prongs provided to themouth cushion, an elbow to deliver breathable gas to the patient, and aheadgear assembly removably connected to the frame so as to maintain themouth cushion and the pair of nasal prongs in a desired position on thepatient's face. The mouth cushion is adapted to sealingly engage aroundan exterior of a patient's mouth in use. The pair of nasal prongs isadapted to sealingly communicate with respective nasal passages of apatient in use. The headgear assembly includes upper headgear straps,lower headgear straps, an upper stabilizing element extending betweeneach upper headgear strap and the frame, and a locking clip provided toeach lower headgear strap that is adapted to be interlocked with a clipreceptacle provided to the frame. Each upper stabilizing element isbendable along at least one bending plane so as to conform to the shapeof a portion of the patient's face.

Another aspect of the invention relates to a mask frame including a mainbody, a side frame portion provided on each lateral side of the mainbody, and a vent assembly provided to each side frame portion. Each ventassembly includes a plurality of holes arranged in a multi-columnpattern and each column is vertically staggered with respect to oneanother.

Another aspect of the invention relates to a mask system for use betweena patient and a device to deliver a breathable gas to the patient. Themask system includes a mouth cushion structured to sealingly engagearound an exterior of a patient's mouth in use, a pair of nasal prongsstructured to sealingly communicate with nasal passages of a patient'snose in use, an elbow to deliver breathable gas to the patient, and aheadgear assembly to maintain the mouth cushion and the nasal prongs ina desired position on the patient's face. The nasal prongs each includea trampoline-like base that adds flexibility to the nasal prongs in use.

Another aspect of the invention relates to a mask system for use betweena patient and a device to deliver a breathable gas to the patient. Themask system includes a mouth cushion structured to sealingly engagearound an exterior of a patient's mouth in use, a pair of nasal prongsstructured to sealingly communicate with nasal passages of a patient'snose in use, and a headgear assembly to maintain the mouth cushion andthe nasal prongs in a desired position on the patient's face. The nasalprongs each include at least a first trampoline-like base that addsflexibility to the nasal prongs in use.

Another aspect of the invention relates to a mask system including aplurality of headgear straps, a sealing assembly, and a stabilizingelement extending between the sealing assembly and at least a selectedone of the headgear straps. The selected headgear strap is adjustablewith respect to the stabilizing element.

Another aspect of the invention relates to a mask system for use betweena patient and a device to deliver breathable gas to the patientcomprising a pair of nasal prongs structured to sealingly communicatewith nasal passages of the patient's nose in use, each of said prongsincluding an inner wall and an outer wall spaced from the inner wallprior to use, said outer wall comprising a membrane that is thinner thanthe inner wall and no more than 0.65 mm thick.

Another aspect of the invention relates to a mask system for use betweena patient and a device to deliver breathable gas to the patient. Themask system includes a pair of nasal prongs structured to sealinglycommunicate with nasal passages of the patient's nose in use. Each ofthe prongs includes a thin membrane. The membrane has a thickness in therange of 0.1 to 0.65 mm.

Other aspects, features, and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles of thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the variousembodiments of this invention. In such drawings:

FIG. 1 is a perspective view of a mask system constructed according toan embodiment of the present invention;

FIG. 2 is a plan view of a first headgear section of a headgear assemblyof the mask system shown in FIG. 1;

FIG. 3 is a plan view of a second headgear section of a headgearassembly of the mask system shown in FIG. 1;

FIG. 4 a is a plan view of the first headgear section shown in FIG. 2and showing dimensions of an embodiment and an embodiment of instructionto form the three-dimensional first headgear section and instructionwhere second headgear section is attached;

FIG. 4 b is a plan view of another embodiment of the first headgearsection;

FIG. 4 c is a plan view of another embodiment of the first headgearsection;

FIG. 4 d is a plan view of another embodiment of the first headgearsection;

FIG. 4 e is a plan view of yet another embodiment of the first headgearsection;

FIG. 4 f is a plan view of still another embodiment of the firstheadgear section;

FIG. 5 is a plan view of the second headgear section shown in FIG. 3 andshowing dimensions of an embodiment;

FIG. 6 is a perspective view of the mask system shown in FIG. 1 removedfrom the patient's head;

FIG. 7 a is a perspective view of the headgear assembly of the masksystem shown in FIG. 1 with the first and second headgear sectionsdetached;

FIG. 7 b is a perspective view of the headgear assembly of the masksystem shown in FIG. 1 with the first and second headgear sectionsattached;

FIG. 8 is a rear perspective view of the mask system shown in FIG. 1 onthe patient's head;

FIG. 9 is a side view of the mask system shown in FIG. 1 on thepatient's head;

FIG. 10 is a rear view of the mask system shown in FIG. 1 on thepatient's head;

FIG. 11 is a front view of another embodiment of a mask system on thepatient's head with X, Y, and Z axes;

FIG. 12 is a side view of the mask system shown in FIG. 1 on thepatient's head with X, Y, and Z axes;

FIG. 13 is a front perspective view of the mask system shown in FIG. 1on the patient's head with the patient pivoting a stabilizing orstabilizer strap;

FIG. 14 is an enlarged perspective view of a frame attachment member ofthe mask system shown in FIG. 1 being engaged with an upper headgearanchor;

FIG. 15 is an enlarged perspective view of the frame attachment membershown in FIG. 14 engaged with the upper headgear anchor;

FIG. 16 is an enlarged perspective view of a frame attachment member ofthe mask system shown in FIG. 1 being engaged with a lower headgearanchor;

FIG. 17 is an enlarged perspective view of the frame attachment membershown in FIG. 16 engaged with the lower headgear anchor;

FIG. 18 is an enlarged perspective view of the frame attachment membershown in FIG. 16 being removed from the lower headgear anchor;

FIG. 19 is a top perspective view of an embodiment of a headgear lockingclip;

FIG. 20 is a bottom perspective view of the headgear locking clip shownin FIG. 19;

FIG. 21 is a side view of the headgear locking clip shown in FIG. 19;

FIG. 22 is an enlarged perspective view of the headgear locking clipshown in FIG. 19 being engaged with a clip receptacle on the frame;

FIG. 23 is an enlarged perspective view of the headgear locking clipshown in FIG. 19 engaged with a clip receptacle on the frame;

FIG. 24 is a perspective view of an embodiment of a mask system withheadgear stabilizing straps attached via a press-stud type interface;

FIG. 25 is a bottom perspective view of the mask system shown in FIG. 24on the patient's face;

FIG. 26 is a perspective view of an embodiment of a mask system with anadjustable chin support;

FIG. 27 is a bottom perspective view of the mask system shown in FIG.26;

FIG. 28 a is a side view of an embodiment of a mask system with chin andcheek supports;

FIG. 28 b is a perspective view of the mask system shown in FIG. 28 a;

FIG. 29 is a rear perspective view of an embodiment of a mask systemwith a “scuba mask” style support;

FIG. 30 is a side perspective view of the mask system shown in FIG. 1;

FIG. 31 is a top view of the frame of the mask system shown in FIG. 1;

FIG. 32 is a side view of the frame of the mask system shown in FIG. 1;

FIG. 33 is a top perspective view of the mask system shown in FIG. 1;

FIG. 34 a is a cross-sectional view of an embodiment of an insertablenasal prong;

FIG. 34 b is a top perspective of a mask system including a cushionhaving a recess adapted to receive the insertable nasal prong shown inFIG. 34 a;

FIGS. 34 c-1 to 34 c-13 illustrate the trampoline effect of the nasalprong according to an embodiment of the present invention;

FIG. 34 d is a cross-sectional view of a nasal prong according toanother embodiment of the present invention;

FIG. 35 is a perspective view that illustrates an embodiment of nasalprong sizes;

FIG. 36 is a perspective view that illustrates an embodiment of nasalprong base sizes;

FIG. 37 is a side view of another embodiment of a nasal prong in a freestate;

FIG. 38 is a side view of the nasal prong shown in FIG. 37 in acompressed state;

FIG. 39 is a front view illustrating the nasal prong shown in FIG. 37engaged with the patient's nose and the mouth cushion moving to theside;

FIG. 40 is a perspective view of a mask system constructed according toanother embodiment of the present invention;

FIG. 41 is a front view of the mask system shown in FIG. 40;

FIG. 42 is a side view of the mask system shown in FIG. 40;

FIG. 43 is an enlarged rear view of the mask system shown in FIG. 40;

FIG. 44 is an enlarged bottom perspective view of the mask system shownin FIG. 43;

FIGS. 45-47 illustrate a mask system according to still anotherembodiment of the present invention;

FIG. 48 is a side view of a mask system according to another embodimentof the present invention;

FIGS. 49-52 illustrate a paired prong arrangement according to anembodiment of the present invention;

FIGS. 52B-52E illustrate a paired prong arrangement according to anotherembodiment of the present invention;

FIGS. 53-56 illustrate a single prong arrangement according to anembodiment of the present invention;

FIGS. 57-58 illustrate a prong including one or more ribs according toan embodiment of the present invention;

FIGS. 59-62 illustrate a prong including a single wall according to anembodiment of the present invention;

FIG. 62B illustrates a single wall nasal prong having a relatively thinwall thickness with beading around a top section thereof according to anembodiment of the present invention;

FIGS. 63-65 illustrate prongs having different upper section profiles;

FIG. 66 illustrates a prong having varying wall sections;

FIG. 66B illustrates nasal prongs according to another embodiment of thepresent invention;

FIGS. 67-70 illustrate a prong including a dual wall according to anembodiment of the present invention;

FIGS. 70B-1 to 70B-10 illustrate a paired-prong arrangement with eachnasal prong including a dual-wall according to an embodiment of thepresent invention;

FIGS. 71-77 illustrate a molding process for constructing a prongincluding a dual wall according to an embodiment of the presentinvention;

FIGS. 78-83 illustrate a molding process for constructing a prongincluding a dual wall according to another embodiment of the presentinvention;

FIGS. 84-89 illustrate a molding process for constructing a prongincluding a triple wall according to an embodiment of the presentinvention;

FIG. 89B illustrates a nozzle assembly including a pair of dual-wallnasal prongs according to an embodiment of the present invention;

FIG. 90 is a front view of a mouth cushion according to an embodiment ofthe present invention;

FIG. 91 is a front view of ResMed's full face mask cushion;

FIG. 92 is a front view of ResMed's mouth mask cushion;

FIG. 93 is a comparison view between cushions of FIGS. 90-92;

FIGS. 94-95 are side and front views of the mouth cushion shown in FIG.90;

FIG. 96 is a cross-sectional view through line 96-96 of FIG. 95, andillustrates comparison between cushions shown in FIGS. 97-98;

FIG. 97 is a cross-sectional view of ResMed's full face mask cushion;

FIG. 98 is a cross-sectional view of ResMed's mouth mask cushion;

FIG. 99-100 are top and bottom view of the mouth cushion shown in FIG.90, and illustrate comparison between cushions shown in FIGS. 102 and103;

FIG. 101 illustrates a membrane curvature of the mouth cushion shown inFIG. 90;

FIG. 102 is a bottom view of ResMed's full face mask cushion;

FIG. 103 is a bottom cross-sectional view of ResMed's mouth maskcushion;

FIGS. 104-106 are cross-sectional views through the mouth cushion shownin FIG. 90, and illustrate comparison between cushion shown in FIG. 108;

FIG. 107 illustrates an undercushion curvature of the mouth cushionshown in FIG. 90;

FIG. 108 is a cross-sectional view of ResMed's full face mask cushion;

FIGS. 109-111 illustrate the width of the mouth cushion shown in FIG.90;

FIG. 111B illustrates exemplary widths of the mouth cushion shown inFIG. 110;

FIGS. 112-119 illustrate wall cross sections along the perimeter of themouth cushion shown in FIG. 90;

FIG. 120 illustrates a frame and upper and lower stabilizing elements ofthe mask system shown in FIG. 48;

FIGS. 120B-120F illustrate cushion attachment to the frame;

FIGS. 121-124 illustrate other views of the frame and upper and lowerstabilizing elements;

FIGS. 124B-124I illustrate various views of the frame including a ventassembly according to an embodiment of the present invention;

FIGS. 125-140 illustrate an elbow assembly according to an embodiment ofthe present invention;

FIGS. 141-143 illustrate upper and lower headgear sections of theheadgear assembly for the mask system shown in FIG. 48;

FIGS. 144-146 illustrate exemplary dimensions for large, medium, andsmall upper headgear sections;

FIGS. 147-149 illustrate exemplary dimensions for large, medium, andsmall lower headgear sections;

FIGS. 150-154 illustrate the headgear assembly of FIGS. 141-143 withupper and lower stabilizing elements assembled and positioned on apatient's head;

FIG. 155 illustrates the mask system shown in FIG. 48 with upper andlower stabilizing elements positioned on a patient's face;

FIGS. 156-158 illustrate an upper stabilizing element according to anembodiment of the present invention;

FIGS. 158 b-1 to 158 b-7 illustrate an upper stabilizing element andframe according to another embodiment of the present invention;

FIGS. 158 c-1 to 158 c-4 illustrate an upper stabilizing element andframe according to another embodiment of the present invention;

FIGS. 159-166 illustrate a lower stabilizing element according to anembodiment of the present invention;

FIGS. 167-170 illustrate assembly of the lower stabilizing element shownin FIGS. 159-166 to clip receptacles provided on the frame;

FIG. 171 illustrates forces provided by the headgear assembly accordingto an embodiment of the present invention;

FIG. 172 illustrates dimensional stability provided by the headgearassembly according to an embodiment of the present invention;

FIGS. 173-175 illustrate upper stabilizing elements according toalternative embodiments of the present invention;

FIGS. 176-177 illustrate alternative arrangements of upper stabilizingelements;

FIGS. 178-181 illustrate a headgear assembly according to anotherembodiment of the present invention;

FIGS. 182-184 illustrate a lower stabilizing element according toanother embodiment of the present invention;

FIGS. 185-189 illustrate a mask system according to another embodimentof the present invention;

FIGS. 190-193 illustrate an elbow according to another embodiment of thepresent invention;

FIGS. 194-196 illustrate a clip member according to another embodimentof the present invention; and

FIG. 197 illustrates a mouth cushion with a “boomerang profile”according to another embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS §1. First IllustratedEmbodiment of Mask System

FIG. 1 illustrates a mask system 210 constructed according to anembodiment of the present invention. As illustrated, the mask system 210includes a sealing assembly 212 that provides an effective seal withboth the patient's mouth and the patient's nasal passages, a swivelelbow 214 to deliver breathable gas to the patient, and a headgearassembly 218 to maintain the sealing assembly 212 in a desired positionon the patient's face. In an embodiment, the swivel elbow 214 may bereplaced with an elbow that is provided to a side of the mask system,e.g., see FIG. 11.

§1.1 Headgear

§1.1.1 Anatomically Shaped Headgear Assembly

As best shown in FIGS. 2, 3, 7 a, and 7 b, the headgear assembly 218includes a first headgear section 220 and a second headgear section 230that is attached to the first headgear section 220. Specifically, thefirst and second headgear sections 220, 230 are constructed fromtwo-dimensional flat headgear material, e.g., soft, flexible compositematerial such as Breathe-O-Prene™ manufactured by Accumed TechnologiesInc. The two-dimensional flat headgear material is stamped, cut, orotherwise manufactured from a sheet, e.g., flexible material withthickness of 0.1-3 mm, to form the desired shapes of the first andsecond headgear sections 220, 230. As shown in FIG. 2 (which illustratesthe first headgear section's bowed final form before it is attached tothe second headgear section 230), the first headgear section 220includes top strap portions 222, bridge strap portions 224, and crownstrap portions 226. The free end of each top strap portion 222 includesa strip of Velcro® material 228 for use in securing the upperstabilizing straps 250 to the headgear assembly 218, and therebysecuring the sealing assembly 212 to the headgear assembly 218. Thedashed lines in FIG. 2 represent possible joint locations of the firstheadgear section 220 to achieve its bowed three-dimension final form. Asshown in FIG. 3 (which illustrates the second headgear section's finalform before it is attached to the first headgear section 220), thesecond headgear section 230 includes bottom strap portions 232 and crownstrap portions 234. The free end of each bottom strap portion 232includes a strip of Velcro® material 238 for use in securing the lowerstabilizing straps 260 to the headgear assembly 218, and therebysecuring the sealing assembly 212 to the headgear assembly 218. FIGS. 2and 3 illustrate the two-dimensional first and second headgear sections220, 230, and FIGS. 4 a and 5 illustrate dimensions of embodiments ofthe first and second headgear sections 220, 230. Although specificdimensions and ranges of the first and second headgear sections 220, 230are shown in FIGS. 4 a and 5, it is to be understood that thesedimensions and ranges are merely exemplary and other dimensions andranges are possible depending on application. For example, ranges thatvary from those provided+/−10% may be suitable for particularapplications.

The two-dimensional first and second headgear sections 220, 230 areattached to one another, e.g., stitched, welded, glued or otherwiseformed, to form a three-dimensional anatomically shaped headgearassembly 218. As shown in FIGS. 4 a, 7 a, and 7 b, the first and secondheadgear sections 220, 230 are attached by attaching ends of respectivecrown strap portions 226, 234. FIG. 6 illustrates the three-dimensionalheadgear assembly 218 attached to the sealing assembly 212, and FIG. 7 billustrate the three-dimensional headgear assembly 218 removed from thepatient's head.

As shown in FIGS. 8-10, the crown strap portions 226, 234 of theheadgear assembly 218 cooperate to form a round-shaped crown strap 240that cups the parietal bone and occipital bone of the patient's head.The crown strap 240 is preferably constructed from at least two segmentsof soft, flexible material that allows the crown strap 240 to conform tothe shape of the patient's head. While the material may be non-elastic,in a preferred embodiment the material is elastic in order to furtherallow the headgear assembly 218 to conform to the patient's head shapeand may be a composite material such as Breathe-O-Prene™ manufactured byAccumed Technologies Inc.

The bridge strap portions 224 of the first headgear section 220 providesadditional stability to the crown strap structure and prevent buckling.The bridge strap portions 224 may be provided to the first headgearsection 220 in multiple arrangements. For example, as shown in FIG. 4 a,the bridge strap portions 224 may be formed, e.g., punched, from thesame piece of material where it remains attached between the top strapportion 222 and the crown strap portion 226. Then, the bridge strapportions 224 may be cut away from respective top strap portions 222 andmoved slightly towards respective crown strap portions 226 where it isreattached, e.g., see dashed lines in FIG. 4 a. This arrangement assistsin forming the first headgear section 220 into the three-dimensionalshape.

In another embodiment, bridge strap portions 224 may not be provided onthe first headgear section 220 as shown in FIG. 4 b.

In another embodiment, the bridge strap portions 224 may be formed,e.g., punched, from the same piece of material and attached between thetop strap portions 222 and the crown strap portions 226, and then leftin its flat configuration as shown in FIG. 4 c.

In another embodiment, the bridge strap portions 224 may be formed,e.g., punched, from the same piece of material as the top strap portions222 and the crown strap portions 226 such that the bridge strap portions224 are separated from respective top strap portions 222 as shown inFIG. 4 d. Then, the bridge strap portions 224 are reattached torespective top strap portions 222 to form a three-dimensional shape.

In yet another embodiment, the bridge strap portions 224 may be formed,e.g., punched, separately from the top strap portions 222 and the crownstrap portions 226 as shown in FIG. 4 e. Then, the bridge strap portions224 are attached between respective top strap portions 222 and crownstrap portions 226 to form a three-dimensional shape.

In still another embodiment, the bridge strap portions 224 may formed,e.g., punched, from the same piece of material as the top strap portions222 and the crown strap portions 226 such that the bridge strap portions224 are separated from respective crown strap portions 226 as shown inFIG. 4 f. Then, the bridge strap portions 224 are reattached torespective crown strap portions 226 to form a three-dimensional shape.The bridge strap portions 224 may also be shortened (e.g., by cutting)if desired before reattaching depending on the particular application.

In still another embodiment, the strap portions of the headgear assemblymay have different elasticity from one another depending on application.

However, the headgear assembly may have other suitable arrangements andforming methods. For example, the straps of the headgear assembly may beattached to one another in other locations to achieve athree-dimensional effect.

The headgear assembly 218 provides several advantages to both themanufacturer and the patient. For example, the formation of athree-dimensional crown strap 240 that fits snugly to the patient's headprevents the buckling of straps that is a recognized problem with someexisting headgear. This increases the patient's comfort and providesstability to the mask system. In addition, the stability provided by thesnug fit of the crown strap 240 allows the headgear assembly 218 to havea relatively small footprint. This in turn provides a relatively smallsurface area in contact with the patient's head, which increases comfortof the patient, e.g., prevents heat formation, areas that press againstthe head when being worn, sweating, etc., and reduces the visual bulk ofthe headgear assembly 218. Also, the formation of the crown strap 240 asdescribed above removes the need to provide adjustment on the headgearassembly 218 that is known with existing headgear, and thus norelatively hard adjustment components that can lead to patientdiscomfort are found. Further, the use of two-dimensional components toconstruct the crown strap 240 provides a relatively low-cost method ofmanufacturing a three-dimensional shape. However, alternative methods ofmanufacture such as molding from heat-setting materials or foam moldedheadgears are possible.

Also, although the headgear assembly 218 has been described inconnection with the mask system 210, it is to be understood that theheadgear assembly 218 may be used in all types of mask systems, e.g.,nasal mask, mouth mask, oro-nasal mask, etc.

§1.1.2 Substantially Rigid Stabilizing Straps

As best shown in FIGS. 1, 11, and 12, upper substantially rigidstabilizing straps 250 are provided between each of the top strapportions 222 and the sealing assembly 212, and lower substantially rigidstabilizing straps 260 are provided between each of the bottom strapportions 232 and the sealing assembly 212. The upper and lowerstabilizing straps 250, 260 provide a flexible yet stable connectionsystem between the headgear strap portions 222, 232 and the sealingassembly 212 in order to ensure suitable tension vectors are provided toseal the sealing assembly 212 with both the patient's mouth and nasalpassages. The desired vectors to achieve a seal to the nares and mouthregion are illustrated in FIG. 171 for example and denoted by F_(X) andF_(Y) specifically.

As illustrated, the stabilizing straps 250, 260, also referred to asstabilizing elements or stiffened headgear elements, are eachconstructed from a rigid or semi-rigid yoke section 244 that is attachedto a material backing 246, e.g., via stitching, welding, gluing, orotherwise mechanically affixed. In the illustrated embodiment, the yokesection 244 is manufactured from nylon or polypropylene orpolycarbonate. However, other materials of greater or less rigidity arealso possible. The stabilizing straps 250, 260 may be constructed frommultiple layers, e.g., more than two layers, or may be constructed froma single layer of substantially rigid material. In an alternativeembodiment, the stabilizing straps may be constructed from a relativelysoft and rigid material so that a material backing is not needed. Thesectional geometry of the yoke section 244 allows flexing across thethickness, i.e., rotation around the Y-axis in FIGS. 11 and 12, toconform to a patient's face, while preventing flexing along thelongitudinal axis, i.e., no rotation around the X-axis in FIGS. 11 and12. In this way, the stabilizing straps 250, 260 act to maintain theposition of the top and bottom strap portions 222, 232 relative to eachother, and secure the mask system 210 at the correct orientation on thepatient's face. In addition, the stabilizing straps 250, 260 act as“outriggers” to the mask system 210 and provide a larger footprint onthe patient's face. This arrangement substantially increases thestability of the mask system.

Another aspect of the design of the headgear assembly 218 is the anglethat the stabilizing straps 250, 260 make with respect to the sealingassembly 212 and the patient's face. In the illustrated embodiment, eachof the upper stabilizing straps 250 makes an angle α of 40°+/−10° withrespect to the horizontal plane H (as defined in FIG. 32) of the sealingassembly 212. This angle α has been chosen as the top strap portions 222are designed to affect sealing in the roughly orthogonal planes of thenasal openings and the mouth opening of the patient. See the vectorsillustrated in FIG. 171 (i.e., along these planes). In this way,tightening the top strap portions 222 will simultaneously draw the nasalprongs 270 of the sealing assembly 212 up and into engagement with thepatient's nares while also drawing the cushion 272 of the sealingassembly 212 back and against the patient's face (particularly above thepatient's upper lip). Thus, the angle chosen and the resultant forcevector when headgear tension is applied allows for effective sealing atboth the nasal prongs 270 and the mouth cushion 272. The angle chosenalso takes into account the various forces the mask system 210 issubject to, e.g., the force desired to seal against the treatmentpressure (as a function of sealing area), and the force desired tooffset tube drag and other factors.

In the illustrated embodiment, each of the lower stabilizing straps 260makes an angle β of 0° to 30° with respect to the horizontal plane H (asdefined in FIG. 32) of the sealing assembly 212. The lower stabilizingstraps 260 are aligned in this manner so that the bottom strap portions232 will extend close to the base of the patient's ear and remainprimarily on the bony part of the patient's skull. This arrangementminimizes the sections of bottom strap portions 232 that extendhorizontally over the patient's neck. In this way, the headgear assembly218 remains firmly attached to the patient's head as there is norelative movement (e.g., distance changes) between headgear componentswhen patient is moving or rolling around and therefore stability of themask system 210 is maximized. By way of explanation, if the headgearextended over the patient's neck it would move or tighten and loosenwith head movements of the patient. This angle also ensures that thebottom strap portions 232 intersect with the crown strap 240 at theappropriate location at the base of the occiput of the patient's head.

§1.1.3 Attachment to Frame

§1.1.3.1 First Embodiment Headgear

As illustrated in FIGS. 1, 11, and 12, the upper stabilizing straps 250are removably connected to an upper portion of the frame 274, and thelower stabilizing straps 260 are removably connected to a lower portionof the frame 274.

As shown in FIGS. 11 and 12, each of the upper and lower stabilizingstraps 250, 260 includes a strap attachment member 254 secured at oneend and a frame attachment member 264 secured at the opposite end. Thestrap attachment member 254 includes a crossbar that enables the endportion of the respective top and bottom strap portion 222, 232 to bewrapped around, in a known manner. The free end of each of the top andbottom strap portions 222, 232 includes a strip of Velcro® material 228,238 that engages the remainder of the strap portion to adjustably pullor secure the strap attachment member 254 in place. Thus, the length ofthe top and bottom strap portions 222, 232 may be easily adjusted.However, other adjustment arrangements are possible, e.g., adjustmentvia ladderlock, ratcheting mechanism, etc.

As best shown in FIGS. 1 and 13, the frame attachment member 264 of eachof the upper and lower stabilizing straps 250, 260 is in the form aswivel attachment that provides a post element 266. The swivelattachment of the upper stabilizing straps 250 is arranged to allowrespective upper stabilizing straps 250 to rotate in one plane in orderto accommodate a wide range of facial angles, as shown in FIG. 13. Theswivel attachment of the lower stabilizing straps 260 is arranged toallow for easy engagement/disengagement.

Specifically, as best shown in FIGS. 1 and 11, the frame 274 includes amain body having a side frame portion 278 on each lateral side thereof.The main body includes an aperture 280 that is coupled to the swivelelbow 214 for delivering breathable gas. Upper and lower anchors 256,258 are provided on each side frame portion 278 thereof. As best shownin FIGS. 14 and 16, each anchor 256, 258 is in the form of a femaleconnector that provides a slot opening 262. Also, as shown in FIG. 31,the upper anchors 256 are substantially in line with the prongs when theprongs are received in the frame 274 (see arcuate dashed line).

In use, each frame attachment member 264 is interlocked with arespective anchor 256, 258 by moving the post element 266 adjacent therespective slot opening 262 such that the post element 266 engageswithin the respective slot opening 262, e.g., with a snap-fit. The frameattachment members 264 on the ends of the upper stabilizing straps 250are adapted to releasably interlock with respective upper anchors 256 onthe frame 274 (see FIGS. 14-15), and the frame attachment members 264 onthe ends of the lower stabilizing straps 260 are adapted to releasablyinterlock with respective lower anchors 258 on the frame 274 (see FIGS.16-18). As shown in FIGS. 16-18, a soft flexible finger tab 268 isprovided on the end of each frame attachment member 264 of the lowerstabilizing straps 260 to facilitate engagement and disengagement of theframe attachment member 264 to the lower anchors 258.

As shown in FIGS. 14 and 15, the slot opening 262 of respective upperanchors 256 is oriented towards the front of the sealing assembly 212 inorder to eliminate inadvertent disengagement. When in use, the force onthe upper stabilizing strap 250 is pulling directly away from therespective slot opening 262, and up against a solid section of the upperanchor 256.

As shown in FIGS. 16-18, the slot opening 262 of respective loweranchors 258 is oriented perpendicular to the front of the sealingassembly 212 in order to allow for easy engagement/disengagement. Thisarrangement provides the mask system 210 with a quick release system sothat the mask system 210 may be removed quickly and easily from thepatient's face in the event of an emergency or panic attack, as shown inFIG. 18.

The headgear attachment points, i.e., anchors 256, 258, are locatedtowards the top and at the lowest point on the frame 274, e.g., seeFIG. 1. This arrangement allows the stabilizing straps 250, 260 toarticulate and rotate as described above, without the stabilizing straps250, 260 having to bend as they run over the top of the frame 274. Thisfreedom of rotation allows the stabilizing straps 250, 260 to conform tothe patient's face.

§1.1.3.2 Second Embodiment

In an alternative embodiment, the frame attachment member of each of thelower stabilizing straps 260 may be in the form of a locking clip 364.As shown in FIGS. 19-21, the locking clip 364 includes upper and lowerarms 365, 367 that are resiliently flexible towards one another. Also,the upper arm 365 includes spaced-apart protrusions 369. In anembodiment, the locking clip 364 is molded in one-piece along with theyoke section 244 of the respective lower stabilizing strap 260.Alternatively, the locking clip 364 may be formed separately from theyoke section 244 and attached thereto, e.g., by an adhesive orrotational connection, etc.

As shown in FIGS. 22-23, the frame 274 is provided with clip receptacles371 on each side frame member thereof. Each clip receptacle 371 includesspaced-apart slots 373. In use, each clip 364 is interlocked with arespective clip receptacle 371 by first moving the clip 364 into therespective clip receptacle 371 such that the protrusions 369 extendthrough respective slots 373 with a snap fit. The clip 364 may bereleased from the respective clip receptacle 371 by depressing the arms365, 367 towards one another until the protrusions 369 release from theslots 373. The clip arrangement may provide audible feedback when theclips 364 are attached to the respective clip receptacles 371.

Also, the clip arrangement may have other suitable designs, such asthose disclosed in U.S. patent application Ser. No. 10/390,681, filedMar. 19, 2003, U.S. patent application Ser. No. 10/655,621, filed Sep.5, 2003, and U.S. Pat. No. 6,374,826, the contents of each being herebyincorporated by reference in its entirety.

§1.1.3.3 Third Embodiment

In another alternative embodiment, the frame attachment member of eachof the upper and lower stabilizing straps 250, 260 may be in the form ofa press-stud type interface. As shown in FIGS. 24-25, the end of eachstabilizing strap 250, 260 includes a protruding stud 465. A softflexible finger tab 468 is provided on the end of each stabilizing strapto facilitate engagement and disengagement to the frame 274.

The frame 274 is provided with stud receivers on each side frame memberthereof. In use, each stud 465 is press-fit into a respective studreceiver. This arrangement allows the stabilizing straps 250, 260 torotate with respect to the frame 274 to allow the mask system to alignon the patient's face. In an alternative embodiment, the studs 465 maybe provided on the frame 274 and the stud receivers may be provided onthe stabilizing straps 250, 260.

§1.1.4 Alternative Stabilizing Systems

FIGS. 26-29 illustrate alternative embodiments for stabilizing the masksystem on the patient's face. For example, FIGS. 26-27 show a masksystem 512 that includes an adjustable chin support 502. As illustrated,the frame of the mask system 512 includes an extension 504 that supportsa V-shaped chin support frame 506. The V-shaped chin support frame 506has two spaced elastomeric chin cushion elements 508 removably attachedthereto and structured to engage a patient's chin. The V-shaped chinsupport frame 506 is moveably mounted to the frame extension 504 toadjust the position of the chin cushion elements 508 relative to thepatient's chin, e.g., by adjusting a thumb screw 509. However, the chinsupport 502 may be adjusted in other suitable manners, e.g., via aratchet-type mechanism, butterfly mechanism, push-button arrangement,tongue/groove arrangement, and/or gear arrangement, as described in U.S.Pat. No. 6,532,961, incorporated herein by reference in its entirety.

FIGS. 28 a and 28 b show a mask system 612 that includes chin and cheeksupports 602, 604 integrally formed with the cushion 672. Asillustrated, the cushion 672 includes a chin support 602 that extendsdownwardly from a lower side wall thereof. The chin support 602 iscontoured to conform to the patient's chin. The cushion 672 alsoincludes a cheek support 604 that extends upwardly from an upper sidewall thereof. The cheek support 604 is contoured to conform to thepatient's cheeks.

FIG. 29 shows a mask system 712 that includes a scuba-style support 702integrally formed with the cushion 772. As illustrated, the support 702extends outwardly from a lower portion and side portions of the cushion772. The support 702 is contoured to conform with chin and cheek regionsof the patient's face that surround the patient's mouth.

§1.2 Mouth Cushion and Frame Shape

As shown in FIGS. 1 and 30-33, the sealing assembly 212 of the masksystem 210 includes a mouth cushion 272 structured to sealingly engagearound an exterior of a patient's mouth in use and a pair of nasalprongs 270 structured to sealingly communicate with the nasal passagesof the patient's nose in use and in particular the base of the patient'snares. The cushion 272 may be integrally formed in one-piece along withthe prongs 270, e.g., by silicone in an injection molding process. Thecushion 272 is structured to be removably and replacably attached to asubstantially rigid frame 274, e.g., by friction fit, mechanicalfastening means, etc. Also, the frame 274 includes an aperture 280 thatis coupled to the swivel elbow 214 for delivering breathable gas.Further, one or more vent openings may be provided in the frame and/orswivel elbow for CO₂ washout. For example, FIGS. 1, 11, 12, and 32illustrate the frame 274 including a vent 281. The vent 281 may have asimilar form to those disclosed in U.S. Provisional Patent ApplicationNo. 60/643,114 to Veliss, filed Jan. 12, 2005, the contents of which arehereby incorporated by reference in their entirety.

In an alternative embodiment, as shown in FIG. 11, opposing ends of themask system may include cylindrical tubes 282, one of which may beprovided with a plug or vent and the other of which may be provided withan elbow 214 for delivering breathable gas. The positions of the elbowand plug/vent may be interchanged, depending on patient preference.

Also, in another embodiment, the mask system (with or withoutcylindrical tubes 282) may be ventless such as the ventless designdescribed in U.S. Patent Application No. 60/667,052, filed Apr. 1, 2005,the contents of which are hereby incorporated by reference in itsentirety.

A low profile is provided by sweeping back the frame 274 immediatelyaround the prongs in order to achieve frame attachment points 256, 258as close as possible to the face without touching the lips. In apreferred embodiment as shown in FIG. 31, the frame 274 is swept back inside frame portions 278 of the frame 274 such that these side frameportions 278 are about 15+/−5 mm below the frame height at which theframe 274 receives the prongs, i.e., the region 276. This arrangementimproves the mouth cushion height to depth ratio and reduces the heightof the mask system 210 on the patient's face. In addition, thisarrangement allows the headgear attachment points 256, 258 to be asclose as possible to the patient's face. Both of these factors combineto improve stability of the mask system 210.

FIG. 33 illustrates the position of the upper headgear anchors 256. Asillustrated, the axis A between the centers of the upper anchors 256lies centrally between the nasal prongs 270 and the upper sealingsurface of the mouth cushion 272. This centralized location enables theheadgear vector to radiate from these points in an orientation that isoptimized for sealing both the nasal prongs 270 and mouth cushion 272.That is, the chosen vector achieves a good balance in compressing thenasal prongs 270 to achieve a comfortable seal in the nose andcompressing the mouth cushion 272 to achieve a comfortable seal at themouth. Concurrently, this vector orientation and location is in a planesuch that the headgear stabilizing straps 250, 260 achieve a tangentialpoint of contact with the cheek region on the patient's face. This isadvantageous for comfort.

Also, the use of a low profile cushion 272 uses less silicone, whicheffectively reduces the weight of the mask system 210. Further, the lowprofile design has the additional benefit of reducing the total internaldeadspace volume of the mask system 210.

§1.3 Nasal Prong Design

The nasal prongs 270 may be formed separately from the cushion 272,e.g., from silicone in an injection molding process, and then insertedand secured to the cushion 272. However, the nasal prongs 270 may beconstructed from other suitable materials, e.g., gel material. Thisarrangement provides a greater scope of patient fitting by being able toselect cushion size and nasal prong size independently. Also, the nasalprongs 270 may be independently aligned (i.e., by rotation of theprongs) with respect to the cushion 272 for optimal fit.

FIG. 34 a shows an embodiment of an insertable nasal prong 270. Asillustrated, the nasal prong 270 is a single prong that includes a nasalportion 284 that sealingly engages with a respective patient naris ornostril and a base portion 286 that is mountable to the cushion 272,e.g., via an annular recess. For example, FIG. 34 b illustrates acushion 272 with an annular recess 273 adapted to receive the baseportion 286 of the prong 270 therein. The base portion 286 of the prong270 may be secured within the recess 273 via a press-fit or glued buttjoint, for example. The single prong arrangement is advantageous becauseit allows customization of fit, e.g., more angular adjustment of theprong to match nasal angle and possibility of different sizes in eachpatient nostril. In an alternative embodiment, the prongs 270 may beprovided as a pair with a thin silicone section joining the prongs atrespective base portions 286. The paired-prong arrangement may improveusability, e.g., improved ease of assembly and alignment.

In the illustrated embodiment, the nasal prong 270 includes atrampoline-like detail at both top and bottom horizontal segments 291,290 of the nasal column 288. As illustrated, the sectional thickness,e.g., nominally 0.75 mm, of the nasal portion 284 and nasal column 288is maintained for a localized area at the base portion 286 of the prong270, i.e., where the nasal column 288 meets the base portion 286 (eitherthe cushion in the case of an integral assembly or the base portion inthe case of insertable prongs), before transitioning into the baseportion 286, e.g., nominally >1.5 mm. This section (indicated byhorizontal segment 290, radial segment 292, and vertical segment 294)acts as a trampoline in use. In the illustrated embodiment, the size andshape (outline) of the trampoline-like base is closely matched, e.g.,identical or close to identical in size, to that of the outer periphery295 of the nasal portion 284. When the nasal prong 270 is brought intocontact with the patient's nose, compression (nasal portion 284 willmove towards base portion 286) will occur. Nasal compression iseffectively the result of the nasal column 288 receding (rolls back ontoitself) into both the nasal portion 284 and base portion 286. Becausethe thickness of these horizontal sections at the top 291 and bottom 290of the nasal column 288 are identical, the nasal column 288 will recedeby a similar degree at both of these locations.

The inclusion of the trampoline-like detail at the top and base of thenasal column 288 has a two-fold effect. First, the increased flexibilityat the top and base of the nasal column 288 allows these transitions toact much like a ball-in-socket arrangement. This allows increasedarticulation of the nasal prong 270, thereby allowing a greater range ofnaso-labial angles to be matched. Second, the compression at the top andbase of the nasal column 288 will act as a form of suspension. In thisway, the mouth cushion 272 can move away from the nasal prongs 270,e.g., move downward or side to side, without disrupting the seal at thepatient's nose. As the mouth cushion 272 moves, the nasal prongs 270 canuncompress while still maintaining sufficient load and hence seal at thepatient's nose.

In an alternative embodiment, the prong design may be modified to removethe radial and vertical segments 292, 294. However, the inclusion ofthese segments is preferred as they maximize the trampoline effect.

FIGS. 34 c-1 to 34 c-13 illustrate the trampoline effect of the nasalprong in greater detail. FIGS. 34 c-1 and 34 c-2 illustrate the nasalprong in its free state. As illustrated, the nasal prong includes anasal or head portion 284 (also referred to as a pillow), a column orstalk 288, a base portion 286 communicated with the mouth cushion volume287, an upper trampoline base 297, and a lower trampoline base 299. Thestalk 288 transitions into the upper and lower trampoline bases 297, 299with radius R1.

As shown in FIG. 34 c-3 and 34 c-4, when the pillow 284 linearlycompresses, the upper trampoline base 297 extends into the pillow's headportion and the lower trampoline base 299 extends into the mouth cushionvolume 287. The overall effect is that the trampoline bases 297, 299flex sufficiently so that the head portion of the pillow 284 can adjustto a height and angle to fit most nostrils. The change in height may berepresented as H (height in free state) minus h (height in compressedstate).

This flexing increases the length of the respective trampoline bases asshown in FIG. 34 c-5. Specifically, L1 represents the stalk 288 andtrampoline base 299 in its free state, and L2 represents the stalk 288and trampoline base 299 in its compressed state. As illustrated, thelength Le2 of the trampoline base in its compressed or flexed state isgreater than the length Le1 of the trampoline base in its free state.The extra material required to increase the length of the trampolinebases comes from the following mechanisms: the trampoline base siliconestretching, and the stalk's end rolling over and being drawn into thetrampoline base as shown in FIGS. 34 c-6 (showing upper trampoline base297 in its free state) and 34 c-7 (showing upper trampoline base 297 inits compressed state).

The stalk 288 has an elliptical section which does not readily rollover. When roll over does occur, resistance to this deformation will actagainst the stalk 288. FIGS. 34 c-3, 34 c-4, 34 c-5, and 34 c-7illustrate the mechanical reactions that occur when the stalk 288 rollsover. As illustrated, the transition radius between stalk 288 andtrampoline base 297, 299 increases to R2 due to the flexible nature ofthe silicone. As a consequence of the radius increasing, the stalk 288will get thinner, e.g., reduce from D to d as illustrated in FIGS. 34c-1 to 34 c-7. The stalk will thin more readily in its weakest plane,which in the case of an elliptical stalk is its minor axis. Also, FIGS.34 c-6 and 34 c-7 provide dots DT to show how material moves into thetrampoline base. In addition, FIG. 34 c-7 shows roll-over action AC androll-over reaction RE that pulls in the stalk 288.

As shown in FIG. 34 c-1, the stalk 288 is a conical tube that merges at90 degrees into the trampoline bases 297, 299 which are conicalsurfaces. The nature of the geometry dictates that the stalk 288 is arelatively rigid member and the adjacent trampoline bases 297, 299 arerelatively flexible members. As shown in FIGS. 34 c-8 and 34 c-9, when anon-axial force F is applied to the head portion of the pillow 284creating a rotational movement to the pillow 284, the pillow 284 willreact in such a way that the trampoline base or bases 297, 299 willrotationally flex around the relatively rigid stalk 288. FIG. 34 c-8illustrates the upper trampoline base 297 rotating about the stalk 288,and FIG. 34 c-9 illustrates the upper and lower trampoline bases 297,299 rotating about the stalk 288.

The trampoline base flexing is a combination of one side stretching andthe other side buckling according to the direction of rotation. Forexample, FIG. 34 c-10 illustrates stretching S and buckling B of thelower trampoline base 299 as the stalk 288 rotates about axis AR.Therefore, the stalk to trampoline base intersection acts as a junctionfor articulation.

A trampoline base 297, 299 provided at the top and bottom of the stalk288 equips the pillow 284 with two articulation junctions, which enablesthe head portion of the pillow 284 to align to most patient nostrils.

In most instances of mask set-up, the pillows 284 will be subjected toboth compression and rotation in order for the head portion of thepillow 284 to adjust in height and angle to conform to the patient'snose and attain seal. The trampoline bases 297, 299 will thereforeexperience the compression and rotation actions mentioned above inunison. FIGS. 34 c-11 to 34 c-13 illustrate some possible compressionand rotation scenarios for the pillow 284. For example, FIG. 34 c-11illustrates the pillow compressed and head portion rotated causing theupper trampoline base 297 to rotate about the stalk. FIG. 34 c-12illustrates the pillow compressed and head portion translated causingthe stalk to rotate about top and bottom trampoline bases 297, 299. FIG.34 c-13 illustrates the pillow compressed and head portion rotatedcausing upper and lower trampoline bases 297, 299 to rotate about thestalk.

In an alternative embodiment, a leaf spring 300 may be provided to abase of the nasal prong 270 as shown in FIG. 34 d. The leaf spring 300may provide substantially similar movement and force that is provided bysections 292 and 294 shown above in FIG. 34 a, e.g. lower trampolinebase.

§1.3.1 Nasal Prong Sizes

In a preferred embodiment, the insertable nasal prongs 270 are providedas a pair. Moreover, the pair may be provided in any one of a number ofdifferent nasal prong sizes and may be anatomically shaped. In FIGS.35-36, the nasal prongs 270 are shown in the position they would takewhen installed on the mouth cushion 272. In addition, the section thatmay join each pair together is not shown. For each of these sizes, thespacing between the two nasal portions 284 is substantially the same,even though the nasal portions 284 themselves are of differing sizes.For example, FIG. 35 illustrates three different sizes of nasal prongs270, i.e., small, medium, and large. As illustrated, the size of thenasal portions 284 changes, but the spacing between the nasal portions284 remains the same.

Also, as noted above, the size of the trampoline base matches that ofthe outer periphery 295 of the nasal portion 284 (see FIG. 34 a). Inorder to allow all insertable prong sizes to interface with an identicalmouth cushion, each size of prong has the same overall base size. Theoverall base size 296 (indicated in dashed lines with diameter D in FIG.36) is the connector or plug that interfaces with the mouth cushion 272.The overall base size 296 is designed to accommodate the largest prongsize, as shown in FIG. 36. For the large size, the axis of the prong 270aligns with the axis of the overall base 296. For the small and mediumsizes, the axis of the prong 270 (and trampoline base) is progressivelyoffset toward the centerline of the prong set so that the separationbetween the nasal portions is identical (Offset−L=0<Offset−M<Offset−S).The section on the base that remains may be greater than about 1.5 mm asabove. This ensures that the trampoline base works similarly oridentically for all sizes.

§1.3.2 Nasal Prong with Articulating Portion

As shown in FIG. 37, the nasal prong 270 may include an articulatingportion 201, or double prong configuration, to add flexibility andarticulation of the nasal prong 270 with respect to the cushion 272. Inthe illustrated embodiment, the nasal prong 270 is structured such thatit is partially “nestable” or significantly compresses once positionedin the patient's nose. For example, FIG. 37 illustrates the nasal prong270 in a free state and FIG. 38 illustrates the nasal prong 270 in acompressed state.

In an embodiment, compression of the nasal prong 270 may be of the orderof about 40%. To achieve this, the articulating portion 201 isstructured such that it has a substantially horizontal lower wall 202.That is, the lower wall 202 of the articulating portion 201 isperpendicular to the lower column 203. This allows the prong 270 tocompress as the lower column 203 moves into the articulating portion201. The nasal portion 284 and upper column 204 of the prong 270 aresimilarly structured although these are marginally stiffer than thearticulating portion 201 and lower column 203. This bias allows thearticulating portion 201 and lower column 203 to compress more readilythan the nasal portion 284 and upper column 204, although compression ofboth sections does occur. The upper portion 205 of the articulatingportion 201 is designed to accommodate the compression of the lowercolumn 203, i.e., there exists sufficient height in the upper portion205 of the articulating portion 201 so that the lower column 203 canmove into this region. In an embodiment, the articulating portion 201 isstructured such that it does not inflate and operate in an extendedmanner.

The selected geometry of the articulating portion 201 allows the prong270 to compress when inserted into the patient's nose. Due to theelastic properties of the silicone (or other compressible material),this compression results in a load that assists in sealing at thepatient's nose and is reacted at the frame. In effect, the prong 270acts as a spring.

The articulating portion 201 allows additional articulation of the prong270 relative to the frame 274 and mouth cushion 272. In operation, thelower column 203 compresses into the articulating portion 201 as shownin FIGS. 38-39. In this way, this articulating portion 201 acts as aball-type joint. The geometry of this arrangement is such that the upperand lower columns 204, 203 remain essentially undeformed with the prong270 pivoting at the junction between the upper column 204 and the lowerwall 206, and the lower column 203 and the lower wall 202. Further, theprong 270 is structured such that the lower column 203 is initiallyaligned with the upper column 204. This arrangement ensures that theload desired to seal the prong 270 at the patient's nose can beeffectively transferred via the headgear attached to the frame.

Also, the compressed prong 270 acts to provide a suspension-type effect,similar to that used in vehicles. In this way, the mouth cushion 272 canmove away from the prong 270, i.e., move downward or side to side,without disrupting the seal at the patient's nose. As the mouth cushion272 moves, the prong 270 can uncompress while still maintainingsufficient load and hence seal at the patient's nose (see FIG. 39).

In the illustrated embodiment, both the nasal portion 284 and thearticulating portion 201 have a substantially elliptical shape. Theshape of the nasal portion 284 ensures substantially even loading acrossa lower surface, and hence even loading into the patient's nose. Thisarrangement dictates that the articulating portion 201 is alsoelliptical in shape so that the load is transferred evenly to the nasalportion 284. However, the prongs 270 may have any other suitable shape,e.g., circular or any other closed section.

§2. Second Illustrated Embodiment of Mask System

§2.1 General

FIGS. 40-44 illustrate a mask system 10 constructed according to anotherembodiment of the present invention. As illustrated, the mask system 10includes a sealing assembly 12 that provides an effective seal with boththe patient's mouth and the patient's nasal passages, inlet conduits 14,16 structured to deliver breathable gas to the patient, and a headgearassembly 18 to maintain the sealing assembly 12 in a desired position onthe patient's face.

The sealing assembly 12 includes a mouth covering assembly 20 having acushion 22 structured to sealingly engage around an exterior of apatient's mouth in use and a nasal prong assembly 24 having a pair ofnasal prongs 26 structured to sealingly engage with the nasal passagesof the patient's nose in use. As illustrated in FIG. 40, the nasal prongassembly 24 is supported by a side wall 32 of the mouth coveringassembly 20. In an embodiment, the mouth covering assembly 20 isintegrally formed in one-piece along with the nasal prong assembly 24,e.g., by silicone in an injection molding process. However, the mouthcovering assembly 20 and nasal prong assembly 24 may be formedseparately from one another and then attached to one another.Advantageously, a standard mouth cushion size can be used in conjunctionwith a variety of nasal prong sizes reducing costs since the multiplemoldings desired for different sized prongs may not be as expensive asmultiple moldings for different sized mouth cushions.

As illustrated, opposing ends of the nasal prong assembly 24 includetubes 28, e.g., cylindrical tubes, that are adapted to engage respectiveinlet conduits 14, 16, e.g., via friction fit. The tubes 28 and inletconduits 14, 16 may have any suitable cross-sectional shape, e.g.,cylindrical, elliptical, flatter section, etc. In use, the inletconduits 14, 16 are supplied with breathable gas under pressure, e.g.,via an air delivery device, and the pressurized breathable gas isdelivered into opposing ends of the nasal prong assembly 24 via thetubes 28. The mouth covering assembly 20 and nasal prong assembly 24 maybe coupled such that gas is allowed to pass between each of these. Thisallows gas to be delivered to both the patient's nasal passages andmouth. Alternatively, the gas may be allowed to pass through the nasalprong assembly 24 only, such that gas is delivered to only the patient'snasal passages. In this arrangement, the mouth covering assembly 20 justacts as a mouth seal. In another embodiment, the gas may be allowed topass through the mouth covering assembly 20 only, such that gas isdelivered to only the patient's mouth. In this arrangement, the nasalprong assembly 24 is blocked and just acts as a nasal seal.

As best shown in FIGS. 43 and 44, the cushion 22 includes anon-face-contacting portion and a face-contacting portion. Thenon-face-contacting portion includes a front wall 30 and a side wall 32extending away from the front wall 30. The front and side walls 30, 32define a chamber for receiving the patient's mouth and a breathable gaswhen communicated to the nasal prong assembly 24. Also, opposing sidesof the cushion 22 include a crossbar 34. Each crossbar 34 extends fromthe side wall 32 and is adapted to releasably engage a lower strap ofthe headgear assembly 18.

The face-contacting portion of the cushion 22 includes a membrane 36that extends from the side wall 32. The membrane 36 is structured toform a seal around the lips of a patient. The face-contacting portion iscontoured to follow generally the curvature of the patient's face. Theface-contacting portion may include one or more undercushions 35 (seeFIG. 43) to provide a support structure for the membrane 36. In anembodiment, the undercushion 35 may have a similar form to thosedisclosed in U.S. Pat. No. 6,701,927, the contents of which are herebyincorporated by reference in its entirety.

The side wall 32 of the cushion 22 supports the nasal prong assembly 24.As illustrated, the nasal prong assembly 24 includes a hollow body 38that defines an air chamber, cylindrical tubes 28 extending from thebody 38, and a pair of nasal prongs 26 supported by a substantially flatrear wall 37 of the hollow body 38. Each nasal prong 26 is substantiallyoval in cross-section and includes a flange or widened portion 40 (alsoreferred to as beads) at an upper end thereof (see FIG. 44). The nasalprongs 26 may be angled with respect to the rear wall 37 to properlyposition the nasal prongs 26 with the nasal passages of the patient.

In the illustrated embodiment, the nasal prongs 26 are in the form ofnasal inserts. In use, the nasal prongs 26 are inserted into thepatient's nasal passages and retained therein by respective flanges 40.One or more vent ports 27 may be provided in a front wall 39 of the body38 for CO₂ washout. In an embodiment, the nasal prong assembly 24 andnasal prongs 26 thereof may have a similar form to those disclosed inU.S. Pat. Nos. 6,478,026 and 6,595,215, the contents of which are herebyincorporated by reference in their entirety. However the nasal prongs 26may be in the form of nasal pillows, nozzles, cannula, nasal puffs, andmay sealingly engage with the patient's nasal passages in any suitablemanner.

As noted above, the body of the nasal prong assembly 24 may include oneor more openings that communicate with one or more openings provided inthe side wall of the cushion 22 to allow breathable gas to pass from theair chamber defined by the body 38 to the air chamber defined by themouth covering assembly 20.

In the illustrated embodiment, the components of the mouth coverassembly 20 and the nasal prong assembly 24 are constructed from asubstantially soft material, e.g., silicone, and may be integrallyformed. However, certain components may be constructed from asubstantially rigid or semi-rigid material, such as the front wall 30,side wall 32, and crossbars or rigid mounting loop 34 of the mouthcovering assembly 20.

§2.2 Headgear Assembly

As best shown in FIGS. 40 and 42, the headgear assembly 18 includes anupper strap 42 removably connectable to the inlet conduits 14, 16 and alower strap 44 removably connectable to the sealing assembly 12.Specifically, the upper strap 42 extends across the patient's foreheadand above the patient's ears. Fastening of the upper strap 42 to thepatient's head may be provided by a hook and loop material, e.g.,Velcro®. The upper strap 42 includes tube retainers 46 that arepositioned adjacent the patient's ears in use. As illustrated, the tuberetainers 46 retain respective inlet conduits 14, 16 so that the inletconduits 14, 16 extend up and around the patient's ears. In anembodiment, each tube retainer 46 is a Velcro® strap that is wrappedaround the respective inlet conduit 14, 16 and upper strap 42.

The lower strap 44 extends around the patients neck and below thepatient's ears. End portions of the lower strap 44 are wrapped around arespective crossbar 34 provided on the cushion 22 and fastened in place,e.g., by a hook and loop material such as Velcro®. However, the lowerstrap 44 may be attached to the cushion 22 in any other suitable manner,e.g., via a clip arrangement. Also, the upper and lower straps 42, 44may be joined to one another, e.g., joined to one another at the back ofthe patient's head similar to the arrangement shown in FIG. 10.

§2.3 Low Profile

As best shown in FIG. 42, the sealing assembly 12 has a low profile,which improves the comfort level of the patient, and reduces the forceswhich may tend to pivot the sealing assembly 12 relative to thepatient's face.

§3. Third Illustrated Embodiment of Mask System

FIGS. 45-47 illustrate a third embodiment of a mask system 410 accordingto the present invention. Mask system 410 is similar to the mask systemsdescribed above, and even includes common elements that have beenindicated with similar reference numbers. For example, mask system 410includes a sealing assembly 412, a swivel elbow 414 and a headgearassembly 418.

The overall architecture of the headgear straps in FIGS. 45-47 issimilar to the overall architecture of the headgear straps in FIG. 12.However, one main difference in the embodiment of FIGS. 45-47 relates tothe use of a stabilizing structure 475. The stabilizing structure 475 inthis example has one end connected to attachment member 464 provided tothe frame and a second end that extends toward top strap portion 422.The second end may be connected to a tab or extension of upper strapattachment member or buckle 454. The stabilizing structure 475,attachment member 464, and buckle 454 may be integrally as a one-piecestructure. Alternatively, the stabilizing structure 475, attachmentmember 464, and buckle 454 may be formed separately from one another andthen assembled to one another.

Stabilizing structure 475 has a “3D” form and is contoured to sit moreflush with the face. In one example, the stabilizing structures aregenerally “S-shaped”, and extend from the patient's temple, along thecheekbones and towards the attachment members 464. The shape also helpsto move the stabilizing structure away from the patient's eyes. Becausethey are generally rigid, stabilizing structures 475 can be slightlyspaced from the patient's cheek region, if desired. The stabilizingstructures may be made of any rigid or semi-rigid material, e.g.,polycarbonate, nylon. The stabilizing structures 475 can also be made ofclear material, to minimize obtrusiveness to the patient.

Headgear assembly may include a padded material or soft portion 477positioned between the stabilizing structure 475 and the patient's face.However, the stabilizing structure 475 may be constructed of arelatively soft material and therefore a padded material may beunnecessary.

Mask system 410 includes a plurality of frame attachment members 464.The frame attachment members 464 associated with the top strap portionsare similar to those shown in FIGS. 14 and 15. The frame attachmentmembers associated with the bottom strap portions are similar to thoseshown in FIGS. 22 and 23.

FIG. 47 also depicts a ports cap 483 for selective attachment of anoxygen delivery cannulae or the like.

§4. Fourth Illustrated Embodiment of Mask System

§4.1 General

FIG. 48 illustrates a mask system 1010 according to another embodimentof the present invention. The mask system 1010 may include one or moreelements that are similar to those of the mask systems described above.As illustrated, the mask system 1010 includes a sealing assembly 1012that provides an effective seal with both the patient's mouth and thepatient's nasal passages, an elbow assembly 1014, e.g., swivel elbow,and a headgear assembly 1018 to maintain the sealing assembly 1012 in adesired position on the patient's face. The mask system 1010 enables thedelivery of therapy in a manner which is unobtrusive, quiet,comfortable, and effective.

The sealing assembly 1012 of the mask system 1010 includes a mouthcushion 1072 structured to sealingly engage around an exterior of apatient's mouth in use and a pair of nasal prongs 1070 structured tosealingly communicate with the nasal passages of the patient's nose inuse. The cushion 1072 is structured to be removably and replacablyattached to a substantially rigid frame 1074.

§4.2 Nasal Prongs

The nasal prongs 1070 may be formed separately from the cushion 1072,e.g., by silicone in an injection molding process, and then inserted andsecured to the cushion 1072. This arrangement provides a greater scopeof patient fitting by being able to select cushion size and nasal prongsize independently.

It should be understood that nasal prongs, nasal pillows, nozzles, orother device that go up or seal near the patient's nose may be used. Inaddition, most people can obtain a good nasal seal with at least one ofthree different sizes of nasal prong. Further, instead of a pair ofnasal prongs (one for each nostril), a single sealing cushion that sealsaround, e.g., just under, both nostrils may be used.

§4.2.1 Paired-Prong Arrangement

FIGS. 49-52 illustrate a paired-prong arrangement wherein nasal prongs1070 are provided as a pair on a single insert. As illustrated, eachnasal prong 1070 includes a nasal portion or head portion 1084 adaptedto sealingly communicate with a respective patient nasal passage and abase portion 1086. The tip of each prong 1070 is slightly inserted intothe nose, with the head portion 1084 engaging the patient's nare. Eachhead portion 1084 includes a curved area 1085 that provides lift orspring to the head portion 1084. The prongs 1070 are joined atrespective base portions 1086 by a bridging or connecting strap 1088,e.g., thin silicone section.

The base portions 1086 are adapted to be mounted to the cushion 1072,e.g., via an annular recess that defines a mounting flange. For example,FIG. 99 illustrates a cushion 1072 with spaced-apart annular recessesthat define flanges 1073 adapted to engage a respective groove providedin each of the base portions 1086 of the prongs 1070 therein. Each baseportion 1086 may be secured within a respective flange 1073 via ainterference-fit or adhesive such as glue, for example. The baseportions 1086 are mounted from the breathing chamber side of the cushion1072 such that the bridging strap 1088 extends along an interior surfaceof the breathing chamber.

The paired-prong arrangement provides head portions 1084 that arepre-aligned with respect to one another. For example, each head portion1084 has a general oval-shape with an oval-shaped nasal opening (seeFIG. 50). The pair of head portions 1084 may be angled with respect toone another to provide a better fit with the patient's nares. As shownin FIG. 50, the head portions 1084 may define an angle A therebetween ofabout 50°-60°, e.g., 54°. However, other angles are possible and may becustomized based on the patient. The paired-prong arrangement providescorrect alignment with the mating cushion 1072 and with the patient'snares. Specifically, the head portions 1084 are pre-angled to match thepatient's nares, the base portions 1086 match the oval shape of theflanges 1073, and the connecting strap 1088 may flex or bend to find itsposition.

In an alternative embodiment, as shown in FIGS. 52B-52E, the major axesof the elliptical head portions 1084 may be parallel to each other,e.g., molded parallel to one another. The bridging strap 1088 may have acircular cross-section (see FIG. 52D). When assembling the prongs 1070onto the cushion 1072, the patient must align the prongs 1070 at anangle as shown in FIG. 52E. The bridging strap 1088 is flexible orbendable to achieve the desired angle. The patient can vary the anglefor either the left or right prong, which allows customization. Thebridging strap 1088 prevents individual left and right prongs 1070 frombecoming separated and lost. Also, the symmetrical design (as the leftand right prongs 1070 are molded parallel) enables easier assembly ontothe cushion. This arrangement also allows the insert to be inserted intothe cushion in different orientations, one being rotated 180° from theother.

The paired-prong arrangement provides correct alignment with the matingcushion 1072 and with the patient's nares because each prong is held inangular alignment with respect to the other prong by nature of itsconnection with the other prong. Also, the paired-prong arrangementprevents accidental loss of component, e.g., loss of nasal prongs. Inaddition, the paired-prong arrangement may improve ease of assembly. Inan embodiment, the prongs 1070 may be configured such that thepaired-prong insert can be inserted into the cushion 1072 in from eitherthe breathing chamber side or the outward facing side, for errorproofing.

§4.2.2 Single-Prong Arrangement

FIGS. 53-56 illustrate a single-prong arrangement wherein a nasal prong1070 is molded and assembled individually to the cushion 1072. Similarto the above, the nasal prong 1070 includes a head portion 1084 and abase portion 1086 adapted to be mounted to the cushion 1072, e.g., via apress-fit or adhesive.

The single prong arrangement is advantageous because it allowscustomization of fit. For example, each nasal prong 1070 may beindependently aligned with respect to the cushion 1072 for optimal fit,e.g., angular adjustment of each prong to match nasal angle. Also, thesingle prong arrangement provides the possibility of different prongsizes in each patient nare, e.g., large prong size for left nare andsmall prong size for right nare.

§4.2.3 Nasal Prong Ribs

As shown in FIGS. 57 and 58, one or more ribs 1090 may be integrallymolded with each nasal prong 1070 to provide axial and radial springand/or lateral/circumferential structural rigidity/reinforcement, e.g.,increased radial strength.

In the illustrated embodiment, multiple ribs 1090 are located internallyon the upper section of the nasal portion or head portion 1084. Themultiple ribs 1090 provide increased radial strength to allow the use ofthin walled head portion 1084 without collapsing. In this way, the headportion 1084 can inflate to a certain degree, to match nasal openingshape, but still retain sufficient rigidity to allow insertion into thenasal opening. Each rib 1090 may be attached or unattached at its base(adjacent the curved area 1085) to control spring rate and stiffness.Also, the cross-sectional thickness of each rib 1090, e.g., rib profile,may vary along its length to control spring rate and stiffness. Clearly,ribs are particularly advantageous where the cushion is formed from avery thin and/or very flexible membrane.

§4.2.4 Single-Wall Nasal Prong

FIGS. 59-62 illustrate another embodiment of a nasal prong 1070 having asingle-wall head portion 1084. As illustrated, the base portion 1086 ofthe nasal prong 1070 includes a slot 1092 to facilitate assembly to thecushion 1072. In addition, the upper flange that defines the slot 1092(e.g., a circumferential groove) includes a curved exterior surface1094, and the lower flange that defines the slot 1092 includes achamfered surface 1096. This arrangement provides a tapered lead-in toallow easier assembly to the cushion 1072.

Also, the section of the nasal prong 1070 (where the nasal column 1087meets the base portion 1086) provides axial spring and compression(e.g., similar to a shock absorber) to compensate for slight variationin angle and distance between the cushion and the patient's nares.Specifically, this section provides a trampoline-type arrangement thatallows the nasal column 1087 to move axially into the base portion 1086.This forms a kind of ball joint which accommodates both short and largeaxial distances to the patient's nares.

The upper section profile of the head portion 1084 may be varied tobetter accommodate nares of different patients. For example, the uppersection profile may have a convex shape (as shown in FIG. 63), astraight shape (as shown in FIG. 64), or a concave shape (as shown inFIG. 65). In an alternative embodiment, the head portion 1084 may beformed of a deformable material, e.g., foam, so that the head portion1084 may be deformed to conform to a patient's nare.

Also, the wall section of the head portion 1084 may be varied to controllateral stiffness/rigidity. For example, FIG. 66 illustrates a headportion 1084 having one wall section (the left side) that is thickerthan an opposing wall section.

§4.2.5 Nasal Prong Length

The nasal prongs are longer than those known in the art, e.g., nasalprongs disclosed in U.S. patent application Ser. No. 10/781,929, filedon Feb. 20, 2004, the entirety incorporated herein by reference. Thisincreased length is desired for a number of reasons.

First, the length of the nasal prong is desired to “reach” to the backof the patient's nose. This is due to the presence of the mouth cushionwhich spaces the base of the prongs from the patient's face.Specifically, the base of the prongs is positioned “behind” the membraneand undercushion that seal on the patient's upper lip. Thus, the prongsmust be longer to extend from the mouth cushion to the patient's nose.In contrast, the nasal prong of the '929 application sits very close tothe patient's face so its length is shorter.

Second, the length of the nasal prong is desired to ensure that sealingon all facial geometries can be satisfied, i.e., to match varyingnaso-labial angles. The mouth cushion precludes rotation of the deviceto match naso-labial angles. Due to the height of the mask, rotationwould result in a large change in distance at the bottom of the mouthcushion, which would present a sealing challenge. In the '929application, the prongs are provided on a “barrel” that can be rotatedto match varying naso-labial angles.

Third, the additional length of the nasal prong section allows greatercompression than that achievable in the '929 application. This in turnsprovides additional sealing at the nose and assists in achieving anappropriate balance of nose and mouth sealing. In addition, compressionat the base of the column will act as a form of “suspension”. In thisway, the mouth cushion can move away from the prong section (i.e., movedownward or side to side) without disrupting the seal at the nose. Asthe mouth cushion section moves, the prong section can uncompress whilestill maintaining sufficient load and hence seal at the nose. This isnot provided in the '929 application as the absence of a mouth cushionmeans the device is much more difficult to disrupt on the face.

In an embodiment, the column or stalk 1087 has a length in the range of9-20 mm. In a preferred embodiment, the stalk 1087 has a length of 12mm.

In an alternative embodiment, nasal prongs 1070 in their free state maybe inset into the mouth cushion 1072 as shown in FIG. 66B. The prongs1070 shown in FIG. 66B may have a length of up to 70 mm. A similarembodiment is disclosed in PCT Application No. PCT/AU2004/001832, filedDec. 24, 2004, which is incorporated herein by reference in itsentirety.

§4.2.6 Articulation

The prong arrangement of the present invention provides independentmovement of both ends of the “stalk” or nasal column of the prong. Hencethe head portion or pillow section can articulate independent of thebase portion or “trampoline” section. This form of independentsuspension allows both axial and rotational movement of the top of theprong. It also allows for the head portion and base portion to remainparallel despite movement or bending of the stalk.

To match the varying naso-labial angles, the prongs are designed toarticulate at both ends. The geometry used allows the joints at each endto act much like “ball in socket” joints and conform to different facialgeometries. The additional length of the prongs allow this articulation(rotation of the prong around its base) without the underside of theprong interfering with the mouth cushion.

§4.2.7 Dual-Wall Nasal Prong

FIGS. 67-70 illustrate a nasal prong 1070 having a dual or double-wallhead portion 1084. As illustrated, the head portion 1084 includes aninner wall 1002 and an outer wall 1004 that surrounds the inner wall1002. In an embodiment, the outer wall 1004 is substantially thinnerthan the inner wall 1002, and no more than 0.65 mm thick. In theillustrated embodiment, the inner and outer walls 1002, 1004 are moldedin its in use position. In use, the thin outer wall 1004 inflates and/orallows conformance to the inner periphery of the patient's nare toenhance the seal of the head portion 1084 against the patient's nare.The dual wall nasal prong may reduce the time of mask set-up as itprovides more ability to seal, e.g., thin outer wall conforms to thepatient's nasal contours. An early generation dual-wall nasal prong isdisclosed in PCT Application No. PCT/AU2004/001832, filed Dec. 24, 2004,which is incorporated herein by reference in its entirety. Also, adual-wall nasal cushion is disclosed in U.S. Pat. No. 6,112,746, whichis incorporated herein by reference in its entirety.

The thin outer wall 1004 (also referred to as an outer membrane) mayhave a thickness in the range of 0.1 mm to 0.65 mm. In a preferredembodiment, the thin outer wall 1004 has a thickness of 0.35 mm. Incontrast, the inner wall 1002 (also referred to as an inner membrane)has a thickness of about 0.75 mm, which is substantially similar to thethickness of the base 1086 and the column or stalk 1087. In otherarrangements, it would also be possible to eliminate the inner wall,just leaving the thinner outer wall membrane for contact with thepatient.

The outer wall 1004 is relatively thin to provide compliance and/orconformance with the patient's nose to enhance the seal of nasal prong1070. That is, the thinner outer wall 1004 allows superior sealing dueto its ability to conform to the nasal contours. The thicker inner wall1002 supports the thinner outer wall 1004 as the prong 1070 is insertedand/or engaged with the patient's nose, e.g., so the outer wall 1004does not collapse. When the prong 1070 is pressurized, the outer wall1004 conforms to the patient's nose and the inner wall 1002 “floats”under the patient's nose, e.g., spaced from the outer wall 1004. Anadequate gap, e.g., 0.75 mm, is provided between the inner wall 1002 andthe outer wall 1004 to allow movement of the inner wall 1002 withoutdisturbing the seal of the outer wall 1004. The gap between the innerand outer walls 1002, 1004 may vary around the perimeter of the headportion 1084 in use, e.g., depending on set-up and/or movement duringuse.

The relatively thin wall thickness, e.g., 0.35 mm, is preferablyprovided to an outer wall of a dual-wall prong configuration. However,the thin wall thickness may be provided to a nasal prong having a singlewall configuration. As noted above, the thin membrane allows superiorsealing due to its ability to conform to the patient's nasal contours.

For example, a nasal prong having a single wall head portion may have awall thickness in the range of 0.1 mm to 0.65 mm, e.g., preferably 0.35mm. In an embodiment, as shown in FIG. 62B, the thin head portion 1084may include a thicker top section or bead 1089 to prevent excessiveflash and/or tearing as the nasal prong 1070 is removed from its mold.

However, the head portion may include other structure to preventexcessive flash and/or tearing. For example, one or more internal ribsmay be added to the head portion 1084, e.g., in lieu of or in additionto beading 1089. As shown in FIGS. 57 and 58, ribs 1090 may be providedto a thin, single wall head portion 1084. In another embodiment, asingle wall head portion may be provided with a tapered or varyingcross-section along its length, e.g., wall thickness tapers fromrelatively thin to thick.

In an alternative embodiment, instead of a one-piece arrangement, a thinouter membrane may be provided as a separate component that is retro-fit(attached, coupled, glued, etc.) to a single wall nasal prong. Forexample, a thin outer membrane may be provided to an exterior surface ofthe head portion and secured in position, e.g., by an elastic ring. Theother membrane 1004 need not be made of the same material (e.g.,Silicone) as the inner wall 1002, so long as it is patient friendly andcompliant.

In a preferred embodiment, the head portion 1084 of the dual wall nasalprong includes a substantially straight conical section s1 that rampsdown to a relatively large elliptical or curved section s2, e.g., seeFIG. 70. The curved section is configured to match the patient's naresopening at the bottom, the conical section improves insertion into thepatient's nose, and dual-wall configuration achieves a quicker moreeffective seal. That is, this profile arrangement has the ability tolocate or insert the head portion into the nose easier, which optimizesset-up time. In use, patients may establish a seal about halfway up thehead portion. This profile arrangement may also be provided in a singlewall nasal prong, e.g., see FIG. 62.

In the illustrated embodiment, the base portion 1086, stalk 1087, headportion 1084, and opening 1069 each include oval or elliptical shapeswhen viewed in plan view, e.g., see FIG. 68. However, other shapes arepossible depending on application, e.g., shape of the patient's nose.For example, the base portion, stalk, head portion, and/or opening mayhave a circular shape. Also, the nasal prong may be configured such thatportions of the prong transition from elliptical to circular shapes,e.g., base portion of the head portion may be generally circular and thehead portion and outlet openings may be elliptical and the prongtransitions therebetween.

In the illustrated embodiments, the dual wall nasal prong has an outerwall 1004 that is longer than the inner wall 1002, e.g., see FIGS. 67and 70. This arrangement may help with sealing and may assist in removalof the dual wall nasal prong from the molding tool. In alternativeembodiments, the outer wall 1004 may be of an equivalent length orshorter than the inner wall 1002.

Also, a surface finish may be added to one or more surfaces of thedual-wall nasal prong. The surface finish may help in removing the nasalprong from its molding tool. In addition, the surface finish may helpwith sealing.

Specifically, a surface finish may be provided on the inner surface ofthe outer wall 1004 to assist removal of the nasal prong from the tool,e.g., a sliding core. A surface finish provided on the outer surface ofthe outer wall 1004 may also help removal of the nasal prong from thetool and may assist sealing with the patient's nare. Similarly, asurface finish may be provided on the inner and/or outer surface of theinner wall 1002 to help removal of the nasal prong from the tool. Asnoted above, beading around the top periphery of the outer wall 1004 maybe applied to prevent excessive flash and/or tearing on removal from thetool.

In addition, the molding tool itself may include surface finish, e.g.,frosted surface finish, to facilitate removal from the nasal prong. Forexample, a surface finish may be added to molding tool surfaces thatengage the inner surface of the outer wall 1004 and/or the outer surfaceof the inner wall 1002. However, the entire exterior surface or portionsof the exterior surface of the tool may have a surface finish.

The base portion 1086 of the dual-wall nasal prong is similar to that ofthe nasal prong having a single-wall, e.g., slot 1092, rounded upperflange 1094, chamfered lower flange 1096, and axial spring section.However, the base of the dual-wall nasal prong may have other suitableconstructions, e.g., such as the base shown in FIGS. 55, 56, and 58.

As described above, the nasal prong includes upper and lowertrampoline-like bases that provide articulation, a self-adjustinglength, and a force for sealing. The trampoline-like base includes twocurved sections at the top and bottom thereof, and a straight section atthe middle thereof. This structure provides the nasal prong with a formof suspension.

Specifically, the trampoline base detail is provided at both ends of thestalk. The trampoline base detail acts as a universal mechanism toarticulate and align the head portion of the pillow to the patient'salar and nasolabial angles, self-adjust the stalk length to suit thepatient's nasolabial height, and/or provide a comfortable sealing forceto the nares. That is, the trampoline base detail allows rotation of thestalk relative to both the head portion of the pillow and the baseportion, and allows reduction in height of the head portion of thepillow relative to the base portion.

FIGS. 70B-1 to 70B-10 illustrate a paired-prong arrangement whereinnasal prongs 1070 are provided as a pair on a single insert. Asillustrated, each nasal prong 1070 includes dual-wall head portion suchas that described above in FIGS. 67-70. The prongs 1070 are joined atrespective base portions by a bridging or connecting strap 1088.

FIGS. 70B-1 to 70B-10 illustrate exemplary dimensions for a paired prongarrangement, e.g., medium size. In the illustrated embodiment, D₁ is10.5 mm, D₂ is 22.5 mm, D₃ is 33.6 mm, D₄ is 38.9 mm, D₅ is 41 mm, D₆ is8 mm, D₇ is 10.3 mm, D₈ is 25.1 mm, D₉ is 4.6 mm, D₁₀ is 7 mm, D₁₁ is20.1 mm, D₁₂ is 14.2 mm, D₁₃ is 9.4 mm, D₁₄ is 66.45 mm, and D₁₅ is 24.5mm. Although specific dimensions are provided, it is to be understoodthat these dimensions are merely exemplary and other dimensions arepossible depending on application. For example, the exemplary dimensionsmay vary by 10-20% or more or less depending on application.

In an embodiment, all internal surfaces of each prong 1070 arerelatively flash free. In addition, the outer wall 1004 is relativelyfree from partlines and flash. Also, the free end of the outer wall 1004is smooth and has a rounded edge, e.g., no sharp edges, and relativelyfree from flash and tears. Further, the entire paired prong arrangementmay be mirror polished, although some selected surfaces may have anon-polished surface finish, e.g., inner surface of outer wall.

In an embodiment, one of the inner and outer walls may be molded in anopen position and then inverted to form the dual wall construction. Thisarrangement simplifies the molding process.

For example, the inner wall 2502 may be molded in an open position (asshown in FIGS. 71-74), and then inverted internally to form the dualwall construction (as shown in FIGS. 75-77). The wall section may bevaried to control stiffness/rigidity. For example, one wall (e.g., innerwall 2502) may be thicker than the other, or both walls may berelatively thin. Also, as shown in FIG. 72, an integrated hinge 2506 maybe provided between the walls 2502, 2504 to control the fold-overlocation.

FIGS. 78-83 illustrate an alternative arrangement wherein the outer wall2604 may be molded in an open position (as shown in FIGS. 78-80), andthen inverted externally with respect to the inner wall 2602 to form thedual wall construction (as shown in FIG. 81-83). The wall section may bevaried to control stiffness/rigidity (e.g., inner wall 2602 (e.g., 0.7mm) thicker than outer wall 2604). In an embodiment, the outer wall 2604acts like a “tacky” filler between the head portion 1084 and thepatient's nare.

FIGS. 84-89 illustrate a nasal prong 1070 having a triple-wallconstruction. It should be understood that the nasal prong 1070 may haveother suitable multi-wall constructions, e.g., head portion 1084 withtwo or more walls. As illustrated, first and second outer walls 2704,2705 may be molded in an open position (as shown in FIGS. 84-86), andthen inverted externally with respect to inner wall 2702 to form thetriple wall construction (as shown in FIG. 87-89). The wall section maybe varied to control stiffness/rigidity. Furthermore, the fold lines maybe positioned differently to achieve a different length fold-overportion.

The dual wall arrangement facilitates sealing of the nasal prong in thenares by combining a structure-defining thicker wall with a seal-formingthinner wall. A very thin wall, while suitable for forming a seal, maylack sufficient stiffness by itself to support the necessary structurein use. As discussed above, adding ribs can stiffen a wall otherwise toothin to support itself in use.

The dual-wall nasal prong may be incorporated into other mask systems.For example, the dual-wall nasal prong may be incorporated into a nozzleassembly such as that disclosed in U.S. patent application Ser. No.10/781,929, filed Feb. 20, 2004, the entirety incorporated herein byreference.

FIG. 89B illustrates an embodiment of such an arrangement. Asillustrated, the nozzle assembly 2810 includes a base portion 2811 and apair of dual-wall nasal prongs 2870 provided thereto. The base portion2811 is adapted to be attached to a frame as described in the '929application. As described above, each dual-wall nasal prong 2870includes a head portion 2884 having an inner wall 2802 and an outer wall2804.

In an embodiment, the outer wall 2804 may have a surface finish appliedto improve manufacturability.

§4.3 Mouth Cushion

As best shown in FIGS. 94, 96, 106 and 120B-120F, the mouth cushion 1072includes a non-face-contacting portion 1038 and a face-contactingportion 1040. The non-face-contacting portion 1038 is structured to beremovably and replacably attached to the frame 1074. In the illustratedembodiment, the non-face-contacting portion 1038 includes an arrow-headtype design having a tapered end portion 1042 with a sealing lip 1044.The tapered end portion 1042 is adapted to be easily inserted andretained, via a retaining bead 1049, within a channel 1075 provided onthe frame 1074 (see FIGS. 121, 167, and 120B-120F). The sealing lip 1044provides a seal around the perimeter of the cushion 1072 and alsoretains the cushion 1072 onto the frame 1074. In an embodiment,alignment features, e.g., diamonds or triangles or other details, may beprovided on the cushion 1072 and frame 1074 to aid correct assembly.Cushion attachment to the frame may be similar to that disclosed in U.S.application Ser. No. 10/390,682, which is incorporated herein byreference in its entirety. However, other cushion attachment methods arepossible.

The face-contacting portion 1040 of the cushion 1072 includes a sidewall 1046, an undercushion 1047 extending away from the side wall 1046,and a membrane 1048 provided to substantially surround the undercushion1047 and provide a sealing structure for the face-contacting portion1040. The inner edge of the membrane 1048 defines an aperture thatreceives the patient's mouth. Also, the side wall 1046 includesspaced-apart prong support structures 1045 that provide annular recesses1073 adapted to support respective prongs 1070 (e.g., see FIGS. 94, 96,112, and 113). As illustrated, the prong support structures 1045 providean angled pedestal that project the prongs at the correct angle to thepatient's nares.

§4.3.1 Shape of Lower Chin Region in Front and Side Views

FIGS. 90-98 illustrate the shape of the cushion 1072 with respect toResMed's full face mask cushion 1200 (shown in isolation in FIGS. 91 and97) and ResMed's mouth mask cushion 1300 (shown in isolation in FIGS. 92and 98). As illustrated in the comparison views of FIGS. 93 and 96, thecushion 1072 has a different shape in the lower chin region when viewedfrom the front and the side.

Specifically, the cushion 1072 is “squarer” (height to width ratiodifferent) at the lower chin region and lower corners of the patient'smouth (area indicated by dots D) when viewed from the front as shown inFIG. 93, as compared to ResMed's full face mask cushion 1200 which ismore curved. This shape of the cushion 1072 covers more of the lowerchin region as indicated by the hatched region in FIG. 93. Also, thisshape of the cushion 1072 better accommodates variations in facialcurvature in the chin region based on anthropometric data. Further, thisshape of the cushion 1072 seals around deep lines radiating from themouth often found on older patients. This provides a better seal whenmouth movements occur during sleep. This change in shape in the lowerchin region (area indicated by dot D) is also illustrated when viewedfrom the side as shown in FIG. 96.

In addition, the cushion 1072 is assymetric about the axis of the mouth(see FIG. 90), whereas ResMed's mouth mask cushion 1300 is symmetricalabout the axis of the mouth (see FIG. 92). Also, the cushion 1072 has asmaller outer radius in the chin region (shown as rl in FIG. 90) thanthe outer radius in the upper lip region (shown as ru in FIG. 90).

§4.3.2 Shape of Membrane at Lower Chin and Upper Lip Regions in Top andBottom Views

FIGS. 99-103 illustrate the shape of the cushion 1072 with respect toResMed's full face mask cushion 1200 (shown in isolation in FIG. 102)and ResMed's mouth mask cushion 1300 (shown in isolation in FIG. 103).As best shown in the comparison views of FIGS. 99 and 100, the membrane1048 of the cushion 1072 is similar in curvature at the chin and upperlip regions when compared to ResMed's full face mask cushion 1200 at thechin area. The curvature of the cushion membrane 1048 at the chin (whenviewed from the bottom as shown in FIG. 100) is substantially similar orthe same as the curvature of the cushion membrane 1048 at the upper lipregion (when viewed from the top as shown in FIG. 99).

As shown in FIG. 101, this curvature of the cushion membrane 1048includes a concave parabolic center region C and two convex curved sideregions S joined to the side walls of the cushion 1072. This arrangementis in contrast to the curvature of ResMed's mouth mask cushion 1300which is defined by a shallower radius (see FIGS. 99 and 100).

§4.3.3 Shape of Undercushion in Top and Bottom Views

FIGS. 104-108 illustrate the shape of the undercushion 1047 with respectto ResMed's full face mask cushion 1200 (shown in isolation FIG. 108).ResMed's mouth mask cushion 1300 does not include an undercushion. Asillustrated in the comparison views of FIGS. 104 and 106, theundercushion 1047 is the same or similar in curvature at the chin andupper lip regions to ResMed's full face mask undercushion 1200.

The curvature of the undercushion 1047 at the chin region (as viewedfrom the bottom in FIG. 106) is the same or similar to the curvature ofthe undercushion 1047 at the upper lip region (as viewed from the top inFIG. 104). This curvature is illustrated in FIG. 107 and includes asubstantially flat center portion C and angled side portions S. Thecenter and side portions are joined together by curved/radii portionsR1. The side portions S merge into a second smaller radius R2 where thecross-sectional cut has been made.

§4.3.4 Width of Undercushion and Membrane at Upper Lip and Chin Regions

As shown in FIGS. 109-110, the width of the undercushion 1047 and themembrane 1048 at the upper lip region is less than the width of theundercushion 1047 and the membrane 1048 at the chin region. The width ofthe undercushion 1047 in the upper lip region is smaller such that itfits in the relatively narrow region between the nares and the upper lip(see FIG. 111) and anthropometric variations in patient population.

In an embodiment, the width of the undercushion 1047 and membrane 1048at the upper lip is between 20% to 80% of the width of the undercushion1047 and membrane 1048 at the chin region. For example, as shown in FIG.111B, dimension A may be about 4 mm, dimension B may be about 6 mm,dimension C may be about 8.8 mm, and dimension D may be about 11 mm.These dimensions may be similar for small and large size cushions.Although specific dimensions are provided, it is to be understood thatthese dimensions are merely exemplary and other dimensions are possibledepending on application. For example, the exemplary dimensions may varyby 10-20% or more or less depending on application.

§4.3.5 Cushion Wall Cross-Section

As shown in FIGS. 112-119, the cross-section of the cushion 1072 variesalong the perimeter of the cushion 1072. In the illustrated embodiment,there are three distinct cross-sections that define the shape of themembrane 1048 and undercushion 1047 along their perimeters. Asillustrated, cross-sections A, B, and C are provided in upper lip, side,and chin regions of the cushion 1072. It is noted that the cross-sectionB is symmetrical on both sides of the cushion 1072. However, alternativeembodiments may utilize more than three cross-sections.

Elements that define each cross-section A, B, and C (for both theundercushion 1047 and the membrane 1048) include angles β and a betweenthe cushion side wall 1046 and the tip of the undercushion 1047 and thetip of the membrane 1048, respectively (see FIG. 117), widths W₁ and W₂from the cushion side wall 1046 to the tip of the undercushion 1047 andmembrane 1048, respectively (see FIG. 118), heights H₁ and H₂ from thetop of the cushion side wall 1046 to the tip of the undercushion 1047and membrane 1048, respectively (see FIG. 119), and radii r1 and r2between the cushion side wall 1046 and the tip of the undercushion 1047and membrane 1048, respectively (see FIG. 118). The undercushion 1047and membrane 1048 of the illustrated embodiments also include straightportions s1 and s2, respectively, at some cross-sections. However, otherelements may be included to define each cross-section.

In an embodiment, the shape or profile of the cushion 1072 may bedefined by three points selected at common points of each of the threecross-sections. At each of the three points, x, y, and z coordinates aredefined, where x dimensions are measured from an anthropometrical datum,y dimensions are measured from a vertical symmetry line, and zdimensions are measured from the cushion height. The shape of thecushion 1072 smoothly varies between the three points along itsperimeter.

§4.4 Frame

As best shown in FIGS. 120-124 and 167, the frame 1074 includes a mainbody 1076 having a side frame portion 1078 on each lateral side thereof.The main body 1076 includes an aperture 1080 and a flanged collar member1082 that surrounds the aperture 1080. The elbow assembly 1014 iscoupled to the flanged collar member 1082 in a manner as describedbelow. The frame 1074 also includes the channel 1075 for retaining thecushion 1072 as described above.

In the illustrated embodiment, a vent assembly 1079 is provided in eachside frame portion 1078 of the frame 1074 for CO₂ washout. The ventassembly may be configured such as those disclosed in U.S. ProvisionalPatent Application Ser. No. 60/795,615, entitled “Nasal Assembly” andfiled Apr. 28, 2006, which is incorporated herein by reference in itsentirety. However, one or more vent openings may be provided in theswivel elbow 1014 for CO₂ washout.

As shown in FIGS. 124B-124I, the vent assembly 1079 is provided in eachside frame portion 1078 of the frame 1074, adjacent the upper anchors1041 described below. Each vent assembly 1079 includes an array orpattern of relatively small holes 1011 arranged in a plurality ofcolumns, e.g., 3-10 columns, and in the example illustrated, 5 columns.The 5 columns are vertically staggered with respect to one another.Also, the first hole in each column cooperate to form an axis A that isangled at an angle α (when viewed from the front as shown in FIG. 124E)of about 15-35°, e.g., 25°, with respect to vertical axis V. As bestshown in the side view of FIG. 124G, each hole is provided along a planeP (approximate plane shown in FIG. 124G due to frame angle in side view)that forms an angle β of about 20-40°, e.g., 30°, with respect tovertical axis V. As shown in the bottom view of FIG. 124H, each hole hasa longitudinal axis L that is angled at an angle of about −10° to 45°,e.g., 0°, with respect to transverse axis T. Each column includes 2-6holes, e.g., 4 holes. In the illustrated embodiment, each hole 1011 hasa generally part conic shape, including opposed walls that converge froma larger diameter to a smaller diameter, as viewed in the direction ofexhausted gas. The smaller diameter may be about 0.7 mm, the largerdiameter may be about 1 mm, the included angle of the cone may be about10° and the height of the cone may be about 1.7 mm. However, other ventarrangements are possible.

As illustrated, the holes 1011 are located away from the aperture 1080to avoid air flow interference. Also, the holes 1011 are located nearheadgear attachment points where the frame 1074 is relatively flat tothe users face for the anchor structures. In addition, the holes 1011are positioned on relatively flat portions of the frame 1074 so that airmay be vented perpendicularly from the general plane of the patient'sface to avoid air jetting towards a bed partner. Thus, this ventarrangement optimizes mask operation and is synergistic in that itutilizes an area of the frame 1074 which is relatively flat to thepatient's face for two purposes, i.e., anchor structure andperpendicular venting. Aesthetics of the frame 1074 are also improvedsignificantly by reducing the number of relatively flat areas that areprovided on the frame 1074.

§4.4.1 Anchor Points for Headgear Assembly

Each side frame portion 1078 includes upper and lower anchors 1041, 1043for attaching the headgear assembly 1018. As best shown in FIGS. 120-124and 167, each upper anchor 1041 is in the form of a female connectorthat provides a slot opening 1062, and each lower anchor is in the formof a clip receptacle 1071. Attachment of the frame 1074 to the headgearassembly 1018 will be described in greater detail below.

The frame 1074 provides four anchor points (as shown in FIGS. 120 and167) for securing the mask system 1010 onto the patient's face. Asillustrated, the anchor points are located at the vertical andhorizontal extremities of the frame 1074 to provide maximum stability byacting as “outrigger” elements.

§4.5 Elbow Assembly

As shown in FIGS. 125-140, the elbow assembly 1014, e.g., swivel elbow,includes an elbow 1051, an anti-asphyxia valve (AAV) 1052, and a clipmember 1053 to secure the AAV 1052 to the elbow 1051.

The elbow 1051 includes a first portion 1081 connectable to the frame1074 and a second portion 1083 connectable to an air delivery tube 1008(see FIGS. 48, 155, and 120). The first portion 1081 of the elbow 1051is releasably connected to the flanged collar member 1082 of the frame1074 in a snap-fit manner as is known from U.S. Patent ApplicationPublication No. 2003/0196656, which is incorporated herein by referencein its entirety.

The elbow 1051 also includes a slot 1091 to receive the AAV 1052, a port1093 that is selectively closed by a flap portion 1063 of the AAV 1052(depending on the presence of pressurized gas), and two recesses orprotrusions (not visible) for attaching the clip member 1053 with asnap-fit.

The AAV 1052 interlocks with the clip member 1053 to provide asub-assembly that is removably attached to the elbow 1051 with asnap-fit. Specifically, the AAV 1052, e.g., constructed of flexiblesilicone or other elastic material, includes an arrowhead-shapedprotrusion 1095 that removably interlocks with a slot 1097 provided onthe clip member 1053, e.g., constructed of rigid plastic. Asillustrated, the inside edges of the slot 1097 are filleted to allow foreasier assembly of the AAV 1052. In addition, the arrowhead shape of theprotrusion 1095 facilitates assembly. However, the inside edges of theslot 1097 may have a conical fillet or chamfer, for example, tofacilitate assembly. Also, the protrusion 1095 of the AAV 1052 may havea filleted, curved, chamfered, or tapered end to facilitate assembly.

The clip member 1053 includes two tabs 1099 that interlock withrespective recesses/protrusions (not shown) provided to the elbow 1051.In addition, the clip member 1053 includes structure to preventincorrect assembly of the AAV 1052 to the elbow 1051.

Specifically, the clip member 1053 includes recessed sides 1033 and acentral vertical rib 1035 integrally molded with the clip member 1053.When the clip member 1053 is assembled to the elbow 1051, the recessedsides 1033 and central vertical rib 1035 are located against the elbowouter surface 1037, e.g., flush against the elbow outer surface, toprevent the AAV 1052 from being assembled between the clip member 1053and the elbow 1051. For example, if the clip member 1053 is assembled tothe elbow 1051 with the AAV 1052 in an incorrect orientation (as shownin FIG. 140 and in dashed lines in FIGS. 137 and 138), the flap portion1063 of the AAV 1052 will be positioned between the central vertical rib1035 and the elbow outer surface 1037, which prevents the clip member1053 from interlocking with the elbow 1051. It would then be evident toa user that the AAV 1052 had not been correctly installed.

In addition, as shown in FIG. 140, the flap portion 1063 of the AAV 1052is longer than the clip member 1053 is wide such that if the AAV 1052 isincorrectly assembled, the flap portion 1063 will extend outside of theclip member 1053 and thereby provide a visual and tactile cue to thepatient that the AAV 1052 has been incorrectly assembly to the elbow1051.

In an embodiment, material, e.g., wall thickness, surrounding the port1093 of the elbow 1051 may be cut-away to reduce material. However,sufficient material is maintained to allow surface area for engaging theflap portion 1063 of the AAV 1052 in use.

Alternative embodiments of the elbow assembly 1014 are disclosed in PCTApplication No. PCT/AU2006/000031, which is incorporated herein byreference in its entirety.

§4.6 Headgear Assembly

As best shown in FIGS. 141-154, the headgear assembly 1018 includes anupper headgear section 1020 and a lower headgear section 1030 that isattached to the upper headgear section 1020. Upper stabilizing elements1050 are provided between the upper headgear section 1020 and the frame1074, and lower stabilizing elements 1060 are provided between the lowerheadgear section 1030 and the frame 1074.

The headgear assembly preferably includes elastic straps, e.g., a pairof upper and a pair of lower elastic straps, and preferably includes therigid or semi-rigid stabilizing elements. The stabilizing elements maybe separate from the elastic straps, may comprise a sub-assembly withthe elastic straps, or may form part of the mask frame In any event, theheadgear assembly defines a sealing force vector having sufficientmagnitude and direction to effect a seal against both the mouth andlower nasal region.

Unlike prior art mask systems including a nasal mask alone, nasal prongsalone, or a full-face mask, the mask system 1010 provides a sealingforce against two surfaces which are almost at right angles to oneanother, namely the mouth and the nares. The headgear straps andstabilizing elements are configured and arranged to achieve sufficientsealing force components in both directions. The headgear of prior artmasks typically only provide a sealing force in one direction orsubstantially in one direction.

The magnitude of the sealing force relates to several factors includingthe elasticity of the headgear straps and how tightly they aretightened. The direction of the sealing force relates to where theheadgear strap is attached to the frame and where it engages with thepatient's head.

The upper straps connect to upper stabilizing elements that in turnconnect to the mask frame in a region which in use lies generallybetween the nose and mouth. In use, the upper straps pass over thepatient's temples and connect with a rear headgear portion thatgenerally engages the occiput of a patient's head. The upper stabilizingelements allow a sufficient force component to seal with the nareswithout obscuring the vision of the patient.

Furthermore, by engagement with rigid or bony regions of the patient'sskull and avoiding non-rigid (e.g., muscle and tendon), the sealprovided by the headgear assembly 1018 is less likely to be disrupted bymovement of the patient's head.

§4.6.1 Headgear Sections

As shown in FIG. 141, the upper headgear section 1020 includes upperstraps 1022, bridge straps 1024, and front crown straps 1026. The freeend of each upper strap 1022 includes a tab of Velcro® material 1028 foruse in securing the upper stabilizing elements 1050 to the upperheadgear section 1020 (see FIG. 143). The Velcro® tab 1028 may besecured to the upper strap 1022 by ultrasonic welding, for example. Inthe illustrated embodiment, the bridge straps 1024 are formed, e.g.,punched, from the same piece of material as the upper straps 1022 andthe front crown straps 1026 such that the bridge straps 1024 areseparated from respective upper straps 1022 as shown in FIG. 141. Then,the bridge straps 1024 are attached to respective upper straps 1022 toform a three-dimensional shape. This arrangement is similar to thatshown in FIG. 4 d.

As shown in FIG. 142, the lower headgear section 1030 includes lowerstraps 1032 and rear crown straps 1034. The free end of each lower strap1032 includes a tab of Velcro® material 1036 for use in securing thelower stabilizing elements 1060 to the lower headgear section 1030 (seeFIG. 143). The Velcro® tab 1036 may be secured to the lower strap 1032by ultrasonic welding, for example.

FIGS. 141 and 142 illustrate the two-dimensional upper and lowerheadgear sections 1020, 1030, and FIGS. 144-149 illustrate dimensions ofembodiments of the upper and lower headgear sections 1020, 1030.Specifically, FIGS. 144-146 illustrate exemplary dimensions for large,medium, and small upper headgear sections 1020, respectively, and FIGS.147-149 illustrate exemplary dimensions for large, medium, and smalllower headgear sections 1030, respectively. In an embodiment, as shownin FIGS. 144-146, LD₁ is 153 mm, MD₁ is 128 mm, MD₂ is 147°, MD₃ is 119mm, MD₄ is 18 mm, MD₅ is 33°, MD₆ is 76.9 mm, MD₇ is 118.9 mm, MD₈ is 84mm, MD₉ is 18 mm, MD₁₀ is 25 mm, and SD₁ is 107 mm. In an embodiment, asshown in FIGS. 147-148, LD₁ is 245 mm, MD₁ is 220 mm, MD₂ is 147°, MD₃is 18 mm, MD₄ is 25 mm, MD₅ is 107.9 mm, MD₆ is 67 mm, MD₇ is 33°, MD₈is 25°, and SD₁ is 220 mm. Although specific dimensions of the upper andlower headgear sections 1020, 1030 are provided, it is to be understoodthat these dimensions are merely exemplary and other dimensions arepossible depending on application. For example, the exemplary dimensionsmay vary by 10-20%.

The two-dimensional first and second headgear sections 1020, 1030 areattached to one another, e.g., machine sewn butt joints, to form athree-dimensional anatomically shaped headgear assembly 1018. FIGS. 141and 142 illustrate the attachment points in dotted lines, e.g., A joinsto A, B joins to B, C joins to C, and D joins to D. As illustrated, thefree end of each rear crown strap 1034 includes a widened portion 1019to facilitate attachment.

FIGS. 150-154 illustrate the three-dimensional headgear assembly 1018positioned on the patient's head. As illustrated, the crown straps 1026,1034 cooperate to form a round-shaped crown strap that cups the parietalbone and occipital bone of the patient's head. FIG. 141 illustrates across-over point Y where the upper headgear section 1020 crosses overthe crown of the patient's head, and FIG. 142 illustrates a cross-overpoint Z where the lower headgear section 1030 crosses over the lowerocciput of the patient's head (i.e., bony structure at the back of thepatient's head).

§4.6.2 Stabilizing Elements

As best shown in FIGS. 48 and 155, the upper and lower stabilizingelements 1050, 1060 provide a stable connection system between the upperand lower straps 1022, 1032 and the sealing assembly 1012 in order toprotect and ensure the seal with both the patient's mouth and thepatient's nasal passages. That is, the upper and lower stabilizingelements 1050, 1060 maintain the position of the upper and lower straps1022, 1032 relative to each other, and secure the mask system 1010 atthe correct orientation on the patient's face. The upper and lowerstabilizing elements 1050, 1060 also act as “outriggers” to the frame1074 to provide a larger footprint on the patient's face. This increasesthe stability of the mask system.

§4.6.2.1 Upper Stabilizing Elements

As shown in FIGS. 156-158 (illustrating a left side upper stabilizingelement, the right side upper stabilizing element being symmetrical indesign to the left side), each upper stabilizing element 1050 isconstructed from a rigid or semi-rigid material, e.g., plastic materialor nylon, and includes a three-dimensional shape so as to contour orconform to the shape of a patient's face. As shown by the dotted linesin FIG. 157, each upper stabilizing element 1050 includes at least onebending plane, e.g., two distinct bending planes B1 and B2, that allowsflexing to conform to the shape of a patient's face.

One end of each upper stabilizing element 1050 includes a crossbar 1054that enables the end portion of a respective upper headgear strap 1022to be wrapped around, in a known manner. Each upper strap 1022 includesthe Velcro® band 1028 that engages the remainder of the strap toadjustably secure the crossbar 1054 in place. The opposite end of eachupper stabilizing element 1050 includes a post element 1066. Each postelement 1066 engages within a respective slot opening 1062 provided tothe frame 1074, e.g., with a snap-fit. This attachment is similar tothat shown in FIGS. 11-15 described above.

FIGS. 158 b-1 to 158 b-6 illustrate an alternative embodiment of theupper stabilizing element 2550 that includes structure to preventmisassembly with the frame 1074. As illustrated, the post element 2566of the upper stabilizing element 2550 is supported by opposing endportions 2567, 2569. One of the end portions 2567 is relatively largerthan the other of the end portions 2569. The enlarged end portion 2567provides a key to facilitate assembly of the upper stabilizing element2550 to the frame 1074 in the correct orientation.

As shown in FIG. 158 b-7, each upper anchor 1041 of the frame 1074 isstructured such that sufficient space is provided on only one side ofthe upper anchor 1041 to accommodate the enlarged end portion 2567.Thus, if the upper stabilizing element 2550 is attempted to be engagedin the wrong orientation with the upper anchor 1041, the enlarged endportion 2567 will prevent the post element 2566 from interlocking withthe respective slot opening 1062 of the upper anchor 1041.

FIGS. 158 c-1 to 158 c-4 illustrate another embodiment of an upperstabilizing element 2650 and a frame 2674 having an upper anchor 2641structured to accommodate such upper stabilizing element 2650. FIGS. 158c-1 and 158 c-2 show a right side upper stabilizing element 2650, andFIG. 158 c-3 shows a left side upper stabilizing element 2650. Similarto the embodiment described above, each upper stabilizing element 2650includes an enlarged end portion 2667 to prevent misassembly with therespective upper anchor 2641 of the frame 2674. In addition, each upperstabilizing element 2650 includes a keyway or groove 2671 that isadapted to receive a key 2673 provided on a respective upper anchor2641. The keyway 2671 of the right side stabilizing element 2650 is onthe same side of the enlarged end portion 2667 (see FIG. 158 c-2), andthe keyway 2671 of the left side stabilizing element 2650 is on theopposite side of the enlarged end portion 2667 (see FIG. 158 c-3).

FIG. 158 c-4 shows the right side of frame 2674. As illustrated, the key2673 is provided on an outer side of the right upper anchor 2641. Theleft upper anchor (not shown) will have the key located on the innerside thereof. This arrangement ensures that the right side stabilizingelement 2650 can only attach to the right side anchor 2641, and the leftside stabilizing element 2650 can only attach to the left side anchor.Specifically, the key 2673 on the right side anchor 2641 only allows thekeyway 2671 of the right side stabilizing element 2650 to pass, and theenlarged end portion 2667 of the right side stabilizing element 2650 canonly fit on the outer side of the right anchor 2641. Similarly, the keyon the left side anchor only allows the keyway 2671 of the left sidestabilizing element 2650 to pass, and the enlarged end portion 2667 ofthe left side stabilizing element 2650 can only fit on the outer side ofthe left anchor. Thus, the enlarged end portion 2667 and key 2673/keyway2671 ensure that only the correct orientation of the upper stabilizingelements 2650 can take place.

§4.6.2.2 Lower Stabilizing Elements

As shown in FIGS. 159-166, each lower stabilizing element 1060 isconstructed from a rigid or semi-rigid material, e.g., plastic material,and allows flexing to conform to a patient's face. Specifically, eachlower stabilizing element 1060 includes a locking clip 1064 and a tailsection 1065.

The tail section 1065 includes a crossbar 1067 that enables the endportion of a respective lower strap 1032 to be wrapped around, in aknown manner. Each lower strap 1032 includes the Velcro® band 1036 thatengages the remainder of the strap to adjustably secure the crossbar1067 in place. As best shown in FIGS. 161 and 165, the tail section 1065is angled with respect to the locking clip 1064 towards the patient'sface so as to conform to the patient's face. In addition, the tailsection 1065 is relatively thin to allow flexing under the influence ofheadgear tension so as to contour to the shape of a patient's face.

In some embodiments, the tail section 1065 may be markedly shorter ordeleted altogether. In this way, the locking clip acts as described inU.S. patent application Ser. No. 10/390,681, filed Mar. 19, 2003, thecontents being hereby incorporated by reference in its entirety.

§4.6.2.3 Locking Clip

Each locking clip 1064 includes two spring arms 1056 and a central tab1058 between the two spring arms 1056. Each clip 1064 is interlockedwith a respective clip receptacle 1071 provided to the frame 1074 with asnap-fit. Clip attachment is similar to that disclosed in U.S. patentapplication Ser. No. 10/390,681, filed Mar. 19, 2003, U.S. patentapplication Ser. No. 10/655,621, filed Sep. 5, 2003, and U.S. Pat. No.6,374,826, the contents of each being hereby incorporated by referencein its entirety.

As best shown in dashed lines in FIG. 166, each spring arm 1056 and theadjacent tail section 1065 are contoured to provide an ergonomic gripand to provide a tactile cue to help differentiate the lower stabilizingelement 1060 from the frame 1074 during disassembly. Also, each springarm 1056 has raised grips to facilitate finger grip.

The central tab 1058 has a rounded front face surface 1059 (when viewedfrom the top and bottom as shown in FIGS. 163 and 166) to improve easeof assembly into the clip receptacle 1071. Also, as shown in FIGS. 163and 166, the front of the central tab 1058 has a bull-nose shape toprevent the locking clip 1064 from becoming caught/tangled with otherparts during manufacture and assembly as well as to prevent the lockingclip 1064 from becoming caught on the frame 1074 and receptacle 1071during fitting.

In addition, the rear side of the central tab 1058 has a central channel1061 with a wide open mouth that is adapted to engage a tapered rib 1068(see FIGS. 121 and 167) provided in the clip receptacle 1071. Thisarrangement facilitates entry and assembly of the locking clip 1064 intothe clip receptacle 1071. Specifically, an error with alignment of thelocking clip 1064 to the clip receptacle 1071 during assembly iscompensated for by the wide open mouth of the channel 1061, i.e., wideopen mouth allows insertion at wider range of angles, as shown in FIGS.167-170.

§4.6.2.4 Backing Material

A padded backing material or soft portion may be applied on the rearsurface of the upper and lower stabilizing elements 1050, 1060 (i.e.,the surface facing the patient's face) to provide comfort and to preventskin irritation (particularly when the patient is sleeping on his/herside). The backing material may be constructed from the same material asthe headgear straps, e.g., Breathe-O-Prene™ manufactured by AccumedTechnologies Inc. However, other suitable materials could be used, e.g.,foam or cotton. The backing material may be secured to the upper andlower stabilizing elements 1050, 1060 in any suitable manner, e.g.,glued or stitched.

§4.6.2.5 Positioning

FIGS. 48, 155, 171, and 172 illustrate the positioning of the upper andlower stabilizing elements 1050, 1060 on the patient's face in use. Asillustrated, the upper stabilizing element 1050 is contoured so that itdoes not obscure the forward field of view or appear in the patient'speripheral vision. Also, the upper stabilizing element 1050 is contouredso that it conforms to the shape of the patient's face, particularly atthe upper cheek area. The relatively thin cross-section coupled with theinherent flexibility of the plastic material and applied headgear straptension also assist the upper stabilizing element 1050 to conform to theshape of the patient's face.

The lower stabilizing element 1060 is angled (as viewed in FIGS. 161 and165) in order to contour to the shape of the patient's face,particularly at the chin region. The relatively thin cross-section ofthe tail section 1065 coupled with the inherent flexibility of theplastic material and applied headgear strap tension also assist thelower stabilizing element 1060 to conform to the shape of the patient'sface.

As shown in FIG. 171, the headgear assembly provides a force in theY-direction F_(y) to seal under the patient's nares and top of mouth anda force in the X-direction F_(x) to seal around the patient's lowermouth. The sealing plane and sealing force against the patient's naresis indicated at SN, and the sealing plane and sealing force against thepatient's mouth is indicated at SM.

Specifically, the pair of upper straps 1022 defines a first force vector(F_(Y)) that provides a force in the Y-direction and the pair of lowerstraps 1032 defines a second force vector (F_(X)) that provides a forcein the X-direction. As illustrated, the first force vector F_(Y) extendsfrom the upper cheek to the crown and the second force vector F_(X)extends from the lower chin to the lower occiput (i.e., the area wherebone meets muscle at the back of the patient's head). The curvedconfiguration of the upper stabilizing elements 1050 offsets the firstforce vector F_(Y) so that the headgear assembly does obscure thepatient's vision, e.g., headgear assembly is sufficiently clear of thepatient's eyes. For example, the dashed line L in FIG. 171 illustrates aline of force that would cause the mask to move such that the patient'svision would be obscured.

One aspect of this system is the angle that the upper stabilizingelement 1050 makes to the mask frame and face. The angle that has beenchosen is designed to affect sealing in the planes of the nasal openingand the mouth opening. In this way, tightening the upper straps 1022will simultaneously draw the nasal prongs “up” into engagement with thenares while also drawing the mouth cushion “back” against the face(particularly above the upper lip). The angle chosen, and the resultantforce vector when headgear tension is applied, allows for optimalsealing at both the nasal pillows and also at the mouth cushion. Thechosen angle takes into account the various forces the mask is subjectto. These include the force desired to seal against the treatmentpressure (as a function of sealing area), and the force desired tooffset tube drag and other factors. This angle provides the optimalbalance between nose and mouth seal.

In an alternative embodiment, instead of the headgear assemblypositioning and retaining both the mouth cushion and nasal pillows in asealing position, only one of the pair is retained by the headgearassembly, and the other of the two is indirectly positioned. That is,the headgear assembly may provide a sealing force for one of the naresand mouth, and provide a platform for a force for sealing the other ofthe nares and mouth.

For example, the mouth cushion may be held in a sealing position on theface by the headgear assembly and the nasal prongs may be pushed intoposition under the nose by a spring mechanism extending from the mouthcushion. Thus, the headgear assembly may provide a sealing force for thepatient's mouth, and the mouth cushion is used as a platform for aspring force to spring the prongs into sealing engagement with thepatient's nares.

In another example, the nasal prongs may be held in position by headgearand the mouth cushion may be positioned by a spring mechanism extendingfrom the nasal prongs. Thus, the headgear assembly may provide a sealingforce for the patient's nares and provide a platform for a spring forceto spring the mouth cushion into sealing engagement with the patient'smouth. In both examples, a force is provided in two directions to sealthe patient's nose and mouth.

As shown in FIG. 172, the lower circumferential distance from lower chinto the lower occipital region, i.e., the distance spanned by the lowerheadgear straps 1032, and the upper circumferential distance from theupper lip to the crown, i.e., the distance spanned by the upper headgearstraps 1022, remains substantially constant even when the patient's headis rotated sideways or up or down. This dimensional stability allows themask system 1012 to be more securely retained onto the patient's face,i.e., the headgear strap tension is less likely to dramatically changeif the upper and lower circumferential distances are kept substantiallyconstant.

§4.6.2.6 Alternative Embodiments of Upper Stabilizing Elements

FIGS. 173-175 illustrate alternative embodiments of the upperstabilizing elements. For example, as shown in FIG. 173, the frame 1074may include an extension 1077 that supports an upper stabilizing element1550. As illustrated, the upper stabilizing element 1550 has a curvedconfiguration. Intermediate and end portions of the upper stabilizingelement are also supported on the frame by support elements 1555. Eachend of the upper stabilizing element includes a crossbar element 1557that enables attachment to a respective upper strap 1022.

As shown in FIG. 174, the frame 1074 may include an extension 1077 thatsupports an upper stabilizing element 1650. As illustrated, the upperstabilizing element 1650 is bent into a generally U-shapedconfiguration. Intermediate and end portions of the upper stabilizingelement 1650 are also supported on the frame by support elements 1655.Each end of the upper stabilizing element 1650 includes a crossbarelement 1657 that enables attachment to a respective upper strap 1022.

As shown in FIG. 175, the frame 1074 may include an extension 1077 thatsupports a pair of upper stabilizing elements 1750. As illustrated, eachupper stabilizing element 1750 has a curved configuration. Supportelements 1755 extend between the pair of upper stabilizing elements1750. Also, each end of the upper stabilizing elements 1750 includes acrossbar element 1757 that enables attachment to a respective upperstrap 1022.

FIGS. 176-177 illustrate alternative arrangements for moving the upperstabilizing elements away from the patient' eyes. For example, FIG. 176illustrate upper stabilizing elements 1850, 1950, 2050 having differentshapes. FIG. 177 illustrates an upper stabilizing element 2250 with aninverted profile to clear the patient's eyes. In another embodiment, theattachment points 1041 on the frame 1074 may be wider, e.g., by adistance Δd as shown in FIG. 124E, for moving the upper stabilizingelements 1050 away from the patient's eyes. In yet another embodiment,the upper stabilizing element may have an alternative connection to theframe 1074, such as those shown in FIGS. 173-175.

§5. Alternative Embodiments

FIGS. 178-181 illustrate another embodiment of a headgear assembly 2418including upper and lower headgear sections 2420, 2430 attached to oneanother. In the illustrated embodiment, the headgear assembly 2418 mayinclude a different stitching pattern or attachment arrangement withrespect to the headgear assemblies described above, which may facilitatealignment and assembly. Specifically, instead of joints that are angledwith respect to one another, the joints are relatively flat, i.e., notangled. FIGS. 178-181 illustrate the attachment points, e.g., A joins toA, B joins to B, and C joins to C.

As illustrated, the headgear assembly 2418 provides a right-angledjoining geometry that makes the end portions easier to align forjoining. Also, the headgear assembly 2418 moves the joint area away fromwhere the velcro fastens to the headgear, which prevents potentialdamage to the joints, e.g., sewn joints.

FIGS. 182-184 illustrate another embodiment of a lower stabilizingelement 2560 including a locking clip 2564 and a tail section 2565. Thelocking clip 2564 is adapted to be interlocked with a respective clipreceptacle provided to the mask frame and the tail section 2565 isadapted to be attached to a headgear strap.

As illustrated, the tail section 2565 is markedly shorter than the tailsection 1065 of lower stabilizing element 1060 described above. Also,the lower stabilizing element 2560 may not require a padded backingbecause it is shorter and does not contact the patient's face or doesnot contact the patient's face as much as the lower stabilizing element1060. This arrangement provides one less assembly step, e.g., assemblyof backing material, and less material is provided, thereby reducingcosts.

FIGS. 185-189 illustrate another embodiment of a mask system 2610. Asillustrated, the mask system 2610 is substantially similar to the masksystem 1010 described above. In contrast, the mask system 2610 mayinclude lower stabilizing elements 2560 such as those shown in FIGS.182-184. Also, the mask system 2610 may have a “large” size, wherein D1is about 126 mm, D2 is about 119 mm, D3 is about 151 mm, D4 is about 120mm, and D5 is about 349 mm. These dimensions are merely exemplary andother dimensions are possible depending on application, e.g., size.

FIGS. 190-193 illustrate another embodiment of an elbow 2751 for a masksystem. In this embodiment, the elbow 2751 may be a rib formed from athicker wall section of the elbow.

FIGS. 194-196 illustrate another embodiment of a clip member 2853 forsecuring an AAV to an elbow. In this embodiment, the clip member 2853may include an arcuate raised potion that mirrors the shape of the vent.

FIG. 197 illustrates another embodiment of a mouth cushion 3072 with a“boomerang profile”. Specifically, the mouth cushion 3072 includes achin section 3015 that is shaped like a boomerang or an inverted U andis designed to rest between the lower lip and the mental protuberance ofthe patient in use. A full-face cushion including a boomerang profile isdisclosed in U.S. patent application Ser. No. 10/655,622, filed Sep. 5,2003, which is incorporated herein by reference in its entirety.

While the invention has been described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention. Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. In addition, while the invention hasparticular application to patients who suffer from OSA, it is to beappreciated that patients who suffer from other illnesses (e.g.,congestive heart failure, diabetes, morbid obesity, stroke, barriatricsurgery, etc.) can derive benefit from the above teachings. Moreover,the above teachings have applicability with patients and non-patientsalike in non-medical applications.

What is claimed is:
 1. A mask system for use between a patient and adevice to deliver a breathable gas to the patient, the mask systemcomprising: a mouth cushion formed of silicone and structured tosealingly engage around an exterior of a patient's mouth in use; a pairof nasal prongs releasably attached to a side wall of the mouth cushionand structured to sealingly communicate with nasal passages of apatient's nose in use; an elbow to deliver breathable gas to the patientat a pressure elevated above atmospheric pressure; and a headgearassembly to maintain the mouth cushion and the nasal prongs in a desiredposition on the patient's face, wherein each prong includes a baseportion provided to the mouth cushion, a head portion to seal with thepatient's nose, and a stalk to interconnect the base portion and thehead portion, wherein each prong includes a first trampoline-like baseprovided between the head portion and the stalk and a secondtrampoline-like base provided between the stalk and the base portion,wherein the first and second trampoline-like bases allow rotation of thestalk relative to both the head portion and the base portion in use andallow reduction in height of the head portion relative to the baseportion by allowing the stalk to move axially into the base portion andthe head portion in use.
 2. A mask system for use between a patient anda device to deliver a breathable gas to the patient, the mask systemcomprising: a mouth cushion formed of silicone and structured tosealingly engage around an exterior of a patient's mouth in use; a pairof nasal prongs releasably attached to a side wall of the mouth cushionand structured to sealingly communicate with nasal passages of apatient's nose in use; and a headgear assembly to maintain the mouthcushion and the nasal prongs in a desired position on the patient'sface, wherein each prong includes a base portion provided to the mouthcushion, a head portion to seal with the patient's nose, and a stalk tointerconnect the base portion and the head portion, wherein each prongincludes a first trampoline-like base provided between the head portionand the stalk and a second trampoline-like base provided between thestalk and the base portion, wherein the first trampoline-like baseallows an upper end of the stalk to flex at least partly into the headportion in use and the second trampoline-like base allows a lower end ofthe stalk to flex at least partly into the base portion in use so as toallow self-adjustment of a height of the head portion relative to thebase portion in use.
 3. The mask system according to claim 2, wherein alength of the first and/or second trampoline-like bases is variable uponrotational movement and/or axial compression.
 4. The mask systemaccording to claim 2, wherein the stalk has an elliptical cross sectionwith a diameter that is reduced upon compression.
 5. The mask systemaccording to claim 2, wherein the stalk has an uncompressed length inthe range of about 9-20 mm.
 6. The mask system according to claim 5,wherein the length is about 12 mm.
 7. The mask system according to claim2, wherein the stalk has a length of up to 70 mm.
 8. A mask system foruse between a patient and a device to deliver a breathable gas to thepatient, the mask system comprising: a substantially rigid frameincluding one or more vent openings; a mouth cushion provided to theframe, the mouth cushion structured to sealingly engage around anexterior of a patient's mouth in use, the mouth cushion including a sidewall, a undercushion extending away from the side wall, and a membraneprovided to substantially surround the undercushion and provide asealing structure; a pair of nasal prongs formed separately from andselectively attachable to and detachable from the mouth cushion, saidnasal prongs being adapted to sealingly communicate with respectivenasal passages of a patient in use and including a bridging strap tointerconnect the pair of nasal prongs, each said nasal prong including abase having an annular recess that is secured within a respectiveopening provided to the side wall of the mouth cushion, a head to sealwith the patient's nose, and a column to interconnect the base and thehead; a swivel elbow provided to the frame to deliver breathable gas tothe patient; and a headgear assembly to maintain the mouth cushion andthe nasal prongs in a desired position on the patient's face, theheadgear assembly including upper straps adapted to extend over thepatient's ears and lower straps adapted to extend below the patient'sears, and the upper and lower straps include connectors that interfacewith upper and lower headgear connector portions provided on each sideof the frame, the straps being length adjustable via a hook and loopfastening arrangement, wherein the nasal prongs and the bridging strapare formed of silicone, wherein each prong includes a firsttrampoline-like base provided between the head and the column and asecond trampoline-like base provided between the column and the base,wherein the first trampoline-like base allows an upper end of the columnto flex at least partly into the head in use and the secondtrampoline-like base allows a lower end of the column to flex at leastpartly into the base in use so as to allow self-adjustment of a heightof the head relative to the base in use.
 9. A mask system for usebetween a patient and a device to deliver a breathable gas to thepatient, the mask system comprising: a substantially rigid frame; amouth cushion provided to the frame, the mouth cushion structured tosealingly engage around an exterior of a patient's mouth in use; a pairof nasal prongs formed separately from and selectively attachable to anddetachable from a side wall of the mouth cushion, said nasal prongsbeing adapted to sealingly communicate with respective nasal passages ofa patient in use and including a bridging strap to interconnect the pairof nasal prongs, a swivel elbow provided to the frame to deliverbreathable gas to the patient; and a headgear assembly to maintain themouth cushion and the nasal prongs in a desired position on thepatient's face, wherein the nasal prongs and the bridging strap areformed of silicone, wherein each prong includes a base portion providedto the mouth cushion, a head portion to seal with the patient's nose,and a stalk to interconnect the base portion and the head portion,wherein each prong includes a first trampoline-like base providedbetween the head portion and the stalk and a second trampoline-like baseprovided between the stalk and the base portion, wherein the first andsecond trampoline-like bases allow both rotation of the stalk and axialcompression of the stalk into both the head portion and the base portionin use to adjust the height and angle of each prong to conform thepatient's nose and attain seal.
 10. A mask system according to claim 9,wherein the mouth cushion includes a side wall, a undercushion extendingaway from the side wall, and a membrane provided to substantiallysurround the undercushion and provide a sealing structure, the membraneand undercushion including spacing therebetween.
 11. A mask systemaccording to claim 10, wherein each nasal prong includes a base havingan annular recess that is secured within a respective opening providedto the side wall of the mouth cushion, a head to seal with the patient'snose, and a column to interconnect the base and the head.
 12. A masksystem according to claim 11, wherein the headgear assembly includesupper straps adapted to extend over the patient's ears and lower strapsadapted to extend below the patient's ears.
 13. A mask system accordingto claim 12, wherein and the upper and lower straps include connectorsthat interface with upper and lower headgear connector portions providedon each side of the frame, the straps being length adjustable via a hookand loop fastening arrangement.
 14. A mask system according to claim 13,wherein the headgear assembly includes a strap that passes over the topof the patient's head.
 15. A mask system according to claim 14, whereinthe mouth cushion includes a chin support integrally formed therewith,the chin support extending from a lower side wall of the mouth cushion.16. A mask system according to claim 15, wherein the frame includes oneor more vent openings.
 17. A mask system according to claim 16, whereineach opening has a part conic shape including opposed walls thatconverge from a larger diameter to a smaller diameter.
 18. A mask systemaccording to claim 17, wherein the swivel elbow includes an elbow havinga port and an anti-asphyxia valve provided to the elbow, theanti-asphyxia valve including a flap portion adapted to selectivelyclose the port depending on the presence of pressurized gas.
 19. A masksystem according to claim 18, wherein the anti-asphyxia valve includesan arrowhead-shaped protrusion that secures the anti-asphyxia valve inposition.
 20. A mask system according to claim 19, wherein the side wallof the cushion includes spaced-apart prong support structures thatprovide respective openings to support respective prongs, the prongsupport structures providing an angled pedestal that projects the prongsat an angle to the patient's nasal passages.
 21. A mask system accordingto claim 20, wherein the mouth cushion includes an end portion that isadapted to be inserted and retained within a channel provided on theframe.
 22. The mask system according to claim 2, wherein each nasalprong includes a dual wall head portion adapted to form a seal with thepatient's nare.
 23. The mask system according to claim 22, wherein thedual wall head portion includes an inner wall and an outer wall thatsurrounds the inner wall.
 24. The mask system according to claim 23,wherein the outer wall is thinner than the inner wall.
 25. A mask systemfor use between a patient and a device to deliver a breathable gas tothe patient, the mask system comprising: a mouth cushion structured tosealingly engage around an exterior of a patient's mouth in use; and apair of nasal prongs formed separately from and selectively attachableto and detachable from the mouth cushion, each prong including a baseportion provided to the mouth cushion, a head portion to seal with thepatient's nose, and a stalk to interconnect the base portion and thehead portion, wherein each prong includes a first trampoline-like baseprovided between the head portion and the stalk, wherein the firsttrampoline-like base allows an upper end of the stalk to axiallycompress at least partly into the head portion in use, and the firsttrampoline-like base allows universal articulation of the head portionrelative to the stalk even if the stalk is substantially fullycompressed into the head portion, and wherein each prong includes asecond trampoline-like base provided between the base portion and thestalk, wherein the second trampoline-like base allows a lower end of thestalk to axially compress at least partly into the base portion in use,and the second trampoline-like base allows universal articulation of thebase portion relative to the stalk even if the stalk is substantiallyfully compressed into the base portion.
 26. A mask system including anasal prong for sealing with a nasal passage of a patient, the nasalprong comprising: a head portion structured to sealingly communicatewith the patient's nasal passage; a stalk including an upper endprovided to the head portion and a lower end, the stalk defining alongitudinal axis, and the lower end including or being connectable to abase portion; wherein, via the first and second trampoline-like bases,the stalk is axially and adjustably movable into the head portion andthe base portion upon application of axial force to change a heightspanning from the head portion to the base portion in dependence onpatient anatomy and/or dynamic movement of the mask system in use. 27.The mask system according to claim 26, further comprising a mouthcushion providing the base portion.
 28. The mask system according toclaim 26, wherein the base portion is provided to the lower end of thestalk.
 29. The mask system according to claim 26, wherein the nasalprong provides universal articulation of the head portion and/or baseportion relative to the stalk even if the stalk is substantially fullycompressed into the head portion and/or base portion.